PIK3R1 and cancer: Table 2 shows the many cancer driver and pathway genes affected in the cell lines by focal CNAs, including TSC2, NF2, BCL6, CHEK2, CDK6, KAT2B, PKD1 and TP63. Among the mechanistic insights, the CNAs suggest relevance for HSP90 inhibition that would be expected to have therapeutic effects through the PI3K and MAPK pathways (e.g., PIK3R1, TSC2, BCL6, NF2, PKD1, and NRAS). Other pathways that are likely to be affected according to our findings are cell cycle progression (e.g., CDKN2A and CCND1) and apoptosis (CASP3).