PIK3R2 and diabetes mellitus: Further correlation analysis indicated the key molecules involved in PI3K-AKT signaling pathway, such as AKT1, AKT2, PIK3R1, and PIK3R2, showed significant positive correlations with AFAP1L2, and in which AKT1 also showed elevated expression in patients without diabetes history (Fig. 4G, H, Additional file 8: Fig. S8F).