IGFBP1 and type 1 diabetes mellitus: We analyzed DNA methylation levels at six CpG sites (referred to as P1 to P6) of the IGFBP1 gene and found that the IGFBP1 DNA methylation levels at five of the six CpG sites were significantly decreased in T1D patients (P1, 16.8%; P2, 14.4%; P3, 11.1%; P4, 11.9%; P6, 19.4%), compared with those in NGT subjects (P1, 17.7%; P2, 15.6%; P3, 12.7%; P4, 13.8%; P6, 22.2%; P = 0.004 for P1, P < 0.001 for P2, P3, P4, P6), except at P5 (19.7% in T1D versus 19.5% in NGT; P = 0.186).