FOXP3 and psoriasis: Forkhead box protein-3 (FOXP3) is a marker of regulatory T cells (Tregs), especially CD4+ Tregs, however, FOXP3 is also expressed in CD8+ T cells (Niederlova et al., 2021) and FOXP3 expression is increased in psoriasis lesions (Fujimura et al., 2008).