PIK3CA and breast cancer: (146) who used droplet digital (ddPCR) of circulating free DNA (cfDNA) to determine the PIK3CA mutation status of 49 patients with early-stage TNBC revealed that PIK3CA mutations are associated with relapse-free survival and breast cancer-specific survival and observed that PIK3CA mutations in TNBC are related to androgen receptor phosphorylation, which is known to be an independent prognostic factor for TNBC.