a. contacting an SMYD3 polypeptide having a methyltransferase activity selected from the group consisting of:

i. a polypeptide comprising the amino acid sequence of SEQ ID NO: 2;

ii. a polypeptide that comprises the amino acid sequence of SEQ ID NO: 2 wherein one or more amino acids are substituted, deleted, or inserted, further wherein said polypeptide has a methyltransferase activity equivalent to the polypeptide consisting of the amino acid sequence of SEQ ID NO: 2;

iii. a polypeptide that comprises the amino acid sequence having at least about 80% homology to SEQ ID NO: 2, wherein said polypeptide has a methyltransferase activity equivalent to the polypeptide consisting of the amino acid sequence of SEQ ID NO: 2;

iv. a polypeptide encoded by a polynucleotide that hybridizes under stringent conditions to a polynucleotide consisting of the nucleotide sequence of SEQ ID NO: 1, wherein the polypeptide has methyltransferase activity equivalent to a polypeptide consisting of the amino acid sequence of SEQ ID NO: 2; and

v. a polypeptide that comprises the amino acid sequence of positions 117 to 246 of the amino acid sequence of SEQ ID NO: 2, wherein said polypeptide has a methyltransferase activity equivalent to the polypeptide consisting of the amino acid sequence of SEQ ID NO:2;

with a VEGFR1 peptide to be methylated and a cofactor in the presence of the agent under conditions suitable for methylation of the VEGFR1 peptide;

b. detecting the methylation level of the VEGFR1 peptide; and

c. comparing the methylation level of step (b) with a control level detected in the absence of the agent,

wherein an increase or decrease in the methylation level compared to the control level indicates that the agent modulates the methylation of VEGFR1 by SMYD3.

a. contacting a VEGFR1 peptide or fragment comprising SMYD3 binding region thereof and an SMYD3 polypeptide or fragment comprising VEGFR1 binding region thereof under a condition that allows the binding of the VEGFR1 peptide and the SMYD3 polypeptide and in the presence of a test compound; and

b. selecting the test compound that inhibits the binding between the or fragment comprising SMYD3 binding region thereof and an SMYD3 polypeptide or fragment comprising VEGFR1 binding region thereof as a candidate compound for treating cancer.

a. identifying a test compound that modulates methylation using the method of claim 1, and

b. selecting the test compound that decreases the methylation level of a substrate to be methylated as compared to a control methylation level detected in the absence of the test compound.

a. an SMYD3 polypeptide having methyltransferase activity selected from the group consisting of:

i. a polypeptide comprising the amino acid sequence of SEQ ID NO: 2;

ii. a polypeptide comprising the amino acid sequence of SEQ ID NO: 2 wherein one or more amino acids are substituted, deleted, or inserted, further wherein said polypeptide has a methyltransferase activity equivalent to the polypeptide consisting of the amino acid sequence of SEQ ID NO: 2;

iii. a polypeptide that comprises the amino acid sequence having at least about 80% homology to SEQ ID NO: 2, wherein said polypeptide has a methyltransferase activity equivalent to the polypeptide consisting of the amino acid sequence of SEQ ID NO: 2;

iv. a polypeptide encoded by a polynucleotide that hybridizes under stringent conditions to a polynucleotide consisting of the nucleotide sequence of SEQ ID NO: 1, wherein the polypeptide has a methyltransferase activity equivalent to a polypeptide consisting of the amino acid sequence of SEQ ID NO: 2; and

v. a polypeptide that comprises the amino acid sequence of positions 117 to 246 of the amino acid sequence of SEQ ID NO: 2, wherein said polypeptide has a methyltransferase activity equivalent to the polypeptide consisting of the amino acid sequence of SEQ ID NO: 2;

b. a VEGFR1 peptide capable of being methylated by the polypeptide of (a), and

c. a cofactor for the methylation of the VEGFR1 peptide.

d. S-adenosyl homocysteine hydrolase (SAHH).

a. contacting a H3K4 methyltransferase with a VEGFR1 peptide to be methylated and a cofactor under the condition capable of methylation of the VEGFR1 peptide;

b. detecting the methylation level of the VEGFR1 peptide; and

c. measuring the methyltransferase activity by correlating the methylation level of step (b) with the methyltransferase activity.

i. a polypeptide comprising the amino acid sequence of SEQ ID NO: 2 (SMYD3);

ii. a polypeptide comprising the amino acid sequence of SEQ ID NO: 2 wherein one or more amino acids are substituted, deleted, or inserted, and said polypeptide has a biological activity equivalent to the polypeptide consisting of the amino acid sequence of SEQ ID NO: 2;

iii. a polypeptide that comprises the amino acid sequence having at least about 80% homology to SEQ ID NO: 2;

iv. a polypeptide encoded by a polynucleotide that hybridizes under stringent conditions to a polynucleotide consisting of the nucleotide sequence of SEQ ID NO: 1, wherein the polypeptide has a biological activity equivalent to a polypeptide consisting of the amino acid sequence of SEQ ID NO: 2; and

v. a polypeptide that comprises the amino acid sequence of positions 117 to 246 of the amino acid sequence of SEQ ID NO: 2, wherein said polypeptide has a methyltransferase activity equivalent to the polypeptide consisting of the amino acid sequence of SEQ ID NO:2.

a. a VEGFR1 peptide capable of being methylated by the SMYD3,

b. a cofactor for the methylation of the VEGFR1 peptide, and

c. a detection regent for detecting methylated of lysine 831.