CD274 and keratoconus: We previously generated transgenic mice (tg) that overexpressed PD‐L1 in basal KCs under the control of the keratin 14 (K14) promoter (K14/PD‐L1tg) and demonstrated that basal KC‐associated PD‐L1 inhibited skin contact hypersensitivity via direct interactions with PD‐1+ CD8+ T cells.8