Our previous studies have suggested that PRKD3 was overexpressed in triple‐negative breast cancer cell lines (MDA‐MB‐468, MDA‐MB‐231).2, 12 In order to study PRKD3 signalling pathway in breast cancer, CRISPR/Cas9 technology was applied for knocking out PRKD3 in the cells. This evidence concerns the gene PRKD3 and breast cancer.