To determine the role of SAP30 in luminal breast cancer development, we generated Sap30-KO mice by deleting exons 2 and 3 of the Sap30 gene with the CRISPR/Cas9 technique (Figure 3A) and crossed these mice with MMTV-PyMT transgenic mice, a well-characterized mouse model of luminal mammary tumor. This evidence concerns the gene SAP30 and breast cancer.