Furthermore, in the analysis of DEGs from the immune system and signal transduction pathways (Supplementary Figure S4), CDKN1A was found to interact with Sox9 and Serpine1, which are involved in T2DM-related signaling pathways, including cAMP, HIF-1, p53, Hippo, Apelin signaling pathways, and the AGE-RAGE signaling pathway in diabetic complications. The gene discussed is APLN; the disease is type 2 diabetes mellitus.