PTPN9 and breast cancer: Lastly, the rs60381548 intronic SNP of the SIN3A gene (Switch-independent 3 family A, a transcriptional regulator previously implicated in BC progression and response to chemotherapy) was associated with its own gene expression, as well as the expression of PTPN9, SNUPN, and SNX33 (30 and 162 kb downstream and 212 kb upstream, respectively).