CD200 and hydrops fetalis: Namely, CD200+ keratinocytes (KCs) located in the outer root sheath (ORF) of murine hair follicles (HFs) act with CD200R+ (positive) leukocytes making them inactivate, which in turn abrogate chemokine-mediated recruitment of other CD200R+ inflammatory cells (macrophage, mast cell) and T cells (also HF-specific autoreactive T cells).