Candidate LCH precursors: myeloid lineages in peripheral blood and tissue. (A) CD45⁺Lineage⁻HLA-DR⁺ subsets from PBMCs (lineage contains CD3, CD19, CD20, and CD56). (i) CD14⁺CD16⁻ classical monocytes. (ii) CD14^lowCD16⁺ nonclassical monocytes. (iii) CD11c⁻CD123⁺ pDCs. (iv) CD11c^lowCD141⁺ mDCs (DC1). (v) CD11c⁺CD1c⁺ mDCs (DC2). (B) CD45⁺HLA-DR⁺ subsets from tissues. (i) AF⁺ macrophages. (ii) CD1a⁺Langerin⁺ LCs. (iii) CD11c⁺CD14⁺ monocytes-macrophages (Mono-Mac). (iv) CD11c^lowCD141⁺ mDCs. (v) CD11c⁺CD1c⁺ mDCs. SSC-A, side scatter area.