PIK3CA and developmental defect during embryogenesis: Somatic variants of PIK3CA, the gene encoding for the catalytic subunit of PI3Kα, are found in breast cancer and in PIK3CA-related overgrowth spectrum (PROS), a group of congenital malformation syndromes that involve vascular, adipose, cutaneous and skeletal malformations, along with segmental overgrowth [2].