L1CAM and cancer: Lugassy et al. (2024) described the migration capabilities of melanoma cells along the outside of vessels, a mechanism termed “extravascular migratory metastasis,” taking a pericyte-like position (Lugassy et al., 2024). Disseminated cancer cells further employ cell adhesion molecule L1 (L1CAM) in pericytes to mediate their adhesion and spreading along the basement membrane of the vasculature; this displaces resident pericytes and facilitates their spread on capillaries through the activation of L1CAM-YAP signaling (Er et al., 2018).