DNMT3A and neoplasm: Furthermore, it was observed that both SETDB1 and DNMT3a expression is essential for gene repression and that both SETDB1 and DNMT3a occupy the P53BP2 (p53 binding protein 2) and RASSF1A (Ras-associated domain family 1A) tumor suppressor loci, thus demonstrating the direct interaction of both SETDB1 and DNMT3a to functionally play a role in endogenous DNA CpG dinucleotide methylation and histone lysine trimethylation [24].