We further compared the levels of PCSK9 between two TNBC cell lines (MDA‐MB‐231 and MDA‐MB‐468) and three non‐TNBC breast cancer cell lines (UACC‐893, SK‐BR‐3, and MCF7) by qPCR and Western blotting analyses. The gene discussed is PCSK9; the disease is breast carcinoma.