ABCB5 and recessive dystrophic epidermolysis bullosa: It is noteworthy in this context that ABCB5+ MSCs-mediated induction of M2 macrophage phenotype switching has been shown to be associated with a significant reduction of tumor necrosis factor-alpha (TNF-α) signaling in the skin [13], while conversely, TNF-α is upregulated and pathophysiologically involved in RDEB [34,35,36].