Studies have shown that SNPs in PDCD1 are associated with a number of autoimmune diseases, including SLE (Fathi et al., 2020), RA (Kong et al., 2005), T1D (Qian et al., 2018), and ankylosing spondylitis (AS) (Liu et al., 2011). Here, PDCD1 is linked to type 1 diabetes mellitus.