In the top 20 pathways, the cGMP-PKG signalling pathway and viral carcinogenesis were the common signalling pathways regulated by Mef2d (Fig. 5B, C, Additional files 1, 2), and the cGMP-PKG signaling pathway was selected for further research due to its noticeable function in T2D-related cardiovascular diseases [27]. The gene discussed is MEF2D; the disease is type 2 diabetes mellitus.