Somatic variants of PIK3CA (OMIM: 171834) are associated with segmental overgrowth disorders, which are now called PIK3CA‐related overgrowth spectrum (PROS) including Fibroadipose (and bone) hyperplasia or overgrowth (FAO), Hemihyperplasia Multiple Lipomatosis (HHML), Congenital Lipomatous Overgrowth, Vascular Malformations, Epidermal Nevi, Scoliosis/Skeletal and Spinal (CLOVES) syndrome; Klippel‐Trenaunay syndrome (KTS) and Megalencephaly‐Capillary Malformation Polymicrogyria (MCAP) syndrome (Keppler‐Noreuil et al., 2015). The gene discussed is PIK3CA; the disease is hemihyperplasia-multiple lipomatosis syndrome.