ARID1A and neoplasm: Noticeably, in Villin-CreER-T2;Arid1afl/fl mice, where Arid1a inactivation is restricted to intestinal epithelial cells, colon epithelium develops invasive ARID1A-deficient adenocarcinoma with prominent mucinous differentiation and presence of tumor-infiltrating lymphocytes as well as MSI, which reflects epithelial cell-intrinsic ARID1A deficiency and is associated particularly with human colorectal cancer (29, 56).