KRT19 and carcinoma: Placing the cells in anchorage-independent growth conditions in the presence of Dox led to a significant (P=0.0001, t-test) increase in colony formation compared with off-Dox control cells (Supplementary Fig. 1c), and implanting HPDE-iKRASG12D cells subcutaneously into the flanks of athymic mice (N=14) led to a rapid formation of poorly differentiated, CK-19-positive carcinomas (N=12) in animals on Dox compared with no tumours observed in animals maintained off Dox (Fig. 2c).