A notable feature in human melanoma metastases is intussusceptive angiogenesis, which divides existing vessels through the creation of internal pillars and depends on MMP9, along with the involvement of macrophages and T cells; such pillars appear infrequently in patient-derived xenografts (PDXs) or models involving BRAF/PTEN alterations, underscoring differences specific to humans [118,131]. Here, BRAF is linked to melanoma.