Immunoblot results showed that the endogenous protein expression level of TM9SF4 was much higher in ovarian cancer lines, including A2780, CaOV3, OVCAR3, COV362 and SKOV3, and breast cancer lines MCF-7 and T47D cells, than in noncancerous lines NIH3T3 and MCF-10A cells (Fig. 1a and Fig. S1a). This evidence concerns the gene TM9SF4 and breast cancer.