Consistent with the results of Chen et al. [31], we detected elevated CA IX levels in basal TNBC cell lines (HS578T, MDA-MB-231, BT-20) and high expression of CA XII in luminal hormone receptor-positive (MCF-7, T47D) or HER2-positive (SKBR3) breast cancer cell lines. The gene discussed is CA9; the disease is breast carcinoma.