Tezza et al. [47] have reported that the adenosine triphosphate- (ATP-) gated iron channel P2X7 receptor (P2X7R) is overexpressed on CD8+ T-cells in T1DM patients, and these, in turn, function to activate CD8+ T-cells upon ATP stimulation. The gene discussed is CD8A; the disease is type 1 diabetes mellitus.