We further examined USP19 expression in normal mammary epithelial cells (MCF‐10A) and BC cells lines (MDA‐MB‐231, MDA‐MB‐468, BT‐549, Hs‐578T, MCF‐7, SK‐BR‐3, T47D, and ZR75‐1) by qRT‐PCR and Western blot. Here, USP19 is linked to breast cancer.