Gut epithelium differentiation (CA4, CA12, CBR1, CHGB, KLF4, KLF9, MCOLN2, SST, TFF3), apoptosis/cell death (CYCS, GSN, KITLG, SST, TFF3, TGFA), cytolisis/crypt damage (ABCB1, KLKR1, PTGER4), formation of aberrant crypt foci (NR5A2, PTGER4), drug transport (ABCB1, ABCG2), migration of tumor cells (EDG2, KITLG, SST, TGFA), quantity of colonocytes (GUCA2A). The gene discussed is ABCG2; the disease is neoplasm.