IFNG and psoriasis: Therefore, to better model human psoriasis where KCs exist in the context of systemically elevated T-cell cytokines, KCs were treated with either tissue culture supernatant from activated human T-cells or recombinant IFNγ (both of which up-regulate ACKR2 expression (16, 24)) and then exposed to tensile stress for 12 h at 0.8 Hz.