PIK3CA and breast cancer: BC cell growth, proliferation and migration, activation of signal transduction pathways (STAT3, PI3K/AKT, GPER/EGFR/ERK1/2; MEK/ERK), epigenetic silencing of tumor suppressor genes, apoptosis, OS, glucose metabolism, angiogenesis, resistance to endocrine therapy [119,122,130];in utero BPA exposure alters the stroma to increase ECM density and mammary gland stiffness [120]; BPA alter the proteolysis and isoform expression by alternative splicing [125]