(a) Normally quiescent basal CK15+ KSCs become Ki67+ as CK-/Ki67+ TAC niche expands in psoriasis, but not in LSC (bar = 50 μm for all panels; broken line = dermal-epidermal junction). (b) Unlike LSC and normal skin, psoriatic lesions show 5-hmC loss (note dermal controls), decreased CK15 (arrow), and nestin upregulation (nestin+ vessel, V; bar = 100 μm for all b&c panels). (c) FABP5 is increased and 5-hmC is decreased in suprabasal TACs in psoriasis (opposed to LSC and normal skin). (d) Quantitative real-time PCR of human psoriatic epidermis showing decreased TET2 expression and increased nestin expression. ** P<0.01, ***P<0.001. Data = mean ± SEM of biological replicates (n=3).