BRAF^V600E-mutated PSCs. Abagnale et al induced PSCs from the peripheral blood mononuclear cells of 2 subjects (1 with childhood-onset LCH, 1 healthy control). They, then, performed genome editing with CRISPR/Cas9 to obtain iPSCs with the BRAF^V600E mutation. The authors differentiated these cells into various cell lineages, including CD34⁺ iHPCs and iMGLs. They found that (1) the iHPCs spontaneously acquired key features of LCH histiocytes and (2) the iMGLs induced neurodegeneration.