DPP9 and interstitial lung disease: In order to simplify the search scope and effectively query the SNPs that may be relevant to the T2DM complicated with ILD, we searched according to the mutated genes which had been identified to be associated with the development of ILD (including familial pulmonary fibrosis) in previous studies, including AKAP13, ATP11A, CDKN1A, DPP9, DSP, ELMOD2, FAM13A, HLA-DRB1, IL1RN, IL8, MAPT, MDGA2, MUC2, MUC5B, OBFC1, SPPL2C, TERC, TERT, TGFB1, TLR3, TOLLIP and TP53 (30).