HDAC1 and colorectal adenocarcinoma: In addition, a recent report shows that Histone Deacetylase 1 and 2 (HDAC1 and 2) have a reciprocal relationship to RB1 and are able to reduce ABCB1 and ABCC2 gene and protein expression in colorectal adenocarcinoma and carcinoma cell lines [40].