We identified somatic variants within 26 of 44 (59%) individuals with slow-flow anomalies (either lymphatic malformation, venous malformation (VM), or mixed lymphatic/venous malformations) within the genes PIK3CA, TEK, GNAQ, BRAF, GNA11, and PIK3R1 with VAFs ranging between 0.7% to 24.8% (Table 1). This evidence concerns the gene PIK3R1 and lymphatic malformation.