Histone acetylation mechanism of OCT2 repression in RCC. In normal renal cells, HDAC7 combines with MYC at the E-box site on OCT2 promoter, resulting in a decrease of free HDAC7s at the promoter, which increases H3K18ac and H3K27ac at the promoter and activates OCT2 expression. However, in RCC cells, the HDAC7-MYC complex is not established, leading to an increase in free HDAC7s at the OCT2 promoter and a decrease in the levels of H3K18ac and H3K27ac, thereby resulting in OCT2 transcriptional inhibition.