IL6 and cancer: Consistent with our hypothesis, YAP overexpression in basal cells or BLBCs, such as MCF-10A, MCF-10A H-RasG12V and 4T1, increased IL6 expression, the percentage of cells with a CD44HiCD24Lo surface antigen profile and mammosphere frequency, whereas it failed to increase IL6 and MaSC-like properties in luminal-type cancer cells, such as MCF-7 and ZR-75-1 (Fig. 9b,c,e).