ARG1 and type 2 diabetes mellitus: Coincubation of HCtAEC with EVs derived from T2D-RBCs increased arginase-1 (ARG1) mRNA levels at 8 hours and 24 hours (Figure 5, E and F) and protein levels (Figure 5, G and H, and Supplemental Figure 7A), whereas no change was observed in arginase-2 (ARG2) mRNA levels (Supplemental Figure 6, C and D).