ALDH1A1 and Bloom syndrome: Since BLM injection induces RALDH1 production in CD103−CD11b− dermal cDCs and subsequently promotes Treg development in WT mice [9], the enhancement of BLM-dependent dermal fibrosis in Fli1+/− mice suggests that Fli1 deficiency impairs the regulatory function of CD103−CD11b− dermal cDCs.