To model this potential cooperativity, we generated a syngeneic BRAFV600E CRC mouse tumor model from C57BL/6 colon organoids with knockout of Adenomatous polyposis coli (APC), TP53 and SMAD4 and expressing BRAFV600E (APC, BRAFV600E, TP53, SMAD4 (ABPS) cells). The gene discussed is SMAD4; the disease is neoplasm.