Previously, we had demonstrated that AA lesions are associated with a massive increase in the number of perifollicular NKG2D+NK cells (Gilhar et al., 2013a), which recognize the activating NKG2D ligand MICA, a ‘danger’ signal that is greatly overexpressed by the epithelium of lesional AA HFs (Ito et al., 2008; Li et al., 2016; Connell and Jabbari, 2022). The gene discussed is MICA; the disease is Hand-foot syndrome.