RAB21 and amyloidosis: Specifically, the proteins involved in amyloidosis, including optineurin (OPTN), ras‐related protein Rab‐21 (Rab21), dynamin 1 (DNM1), peroxisomal bifunctional enzyme (EHHADH), fermitin family homolog 2 (FERMT2), E3 ubiquitin‐protein ligase UBR1 were increased in T2DM‐MCI compared with T2DM‐nMCI (Figure 2b).