TFRC and type 1 diabetes mellitus: The frequency of CD4 + T cells expressing CD69 and CD71 was found to be significantly higher in T1D as compared to HC group (1.67 ± 0.25% vs 0.59 ± 0.2%) (p = 0.002) and (1.27 ± 0.14% vs 0.7 ± 0.17%) (p = 0.01) (Fig. 8c,d), respectively.