A total of 37 studies published between 2003 and 2025 were included, encompassing 148 patients diagnosed with capillary malformation–arteriovenous malformation syndrome (CM-AVM) and genetically confirmed to carry either RASA1 or EPHB4 mutations (Table 1) [1–11, 14, 17, 18, 20–43]. This evidence concerns the gene EPHB4 and cutaneous mastocytosis.