PIK3CA and breast cancer: According to targeted NGS (analysis of the 95 genes most frequently altered in breast cancer) and copy number analysis, LAR TNBC PDX had a genomic profile different from that of the other TNBC subtypes, with enrichment in PIK3CA and AKT1 mutations (100% versus 7,5%, p=0.0002, Fisher's exact test; LAR versus other subtypes), a lower frequency of TP53 mutations (25% for LAR and 52.8% in the other subtypes) and a high frequency of FGFR1 amplification.