XRCC2 and ductal breast carcinoma in situ: There were 143 genes with differential mRNA abundance between breast cancer with and without co-growth of DCIS including XRCC2 (homologous recombination), GNRH1, CACNA1B (calcium signaling, MAPK pathway), PRKAA1 (mTOR pathway), DUSP22 (MAPK pathway), MKNK1 (MAPK/mTOR pathway), and SSBP1 (homologous recombination, mitochondria).