Fig. 1

Methylation analyses of SFRP2 promoter in different tissues in non-CRC subjects and CRC patients, according to the 30th percentile of 25-OH vitamin D. a Methylation average status for the SFRP2 promoter in PBMCs (N = 11; N = 52) and VAT (N = 53; N = 50) from non-CRC and CRC patients, respectively. b Methylation average status for the SFRP2 promoter in CRC tumor area (N = 60) and CRC tumor-free area (N = 55) from CRC patients. c Methylation analyses of seven CpG islands of the SFRP2 promoter in tumor area from CRC patients (N = 60). The results are given as methylation average ± standard deviation. Significant differences between the means of the different groups of subjects were performed according to the Welch’s two sample test (*p < 0.05, **p < 0.01). Abbreviations: SFRP2, Secreted frizzled-related protein type 2; CRC, Colorectal cancer; PBMCs, peripheral blood mononuclear cells; VAT, Visceral adipose tissue