Four genes, namely KRAS (in breast carcinoma, non-small cell lung cancer (NSCLC), lymphoma multiple myeloma carcinoma, colorectal carcinoma, and leukemia), NRAS (in pancreatic carcinoma, bladder carcinoma, primitive neuro-ectodermal tumors (PNET)), PIK3CA (in breast carcinoma and ovarian carcinoma), and ARHGAP31 (in colorectal carcinoma and pancreatic carcinoma) were identified as missense driver genes in more than one cancer type. Here, PIK3CA is linked to breast carcinoma.