Subdividing people with obesity into MetsO and MHO, a negative correlation was also detected between MMP-2 levels, MMP-2/TIMP-2 ratio and CRP values in MetsO (r = − 0.26, p = 0.03, r = − 0.27, p = 0.03, respectively, Supplementary Table 2). The gene discussed is CRP; the disease is obesity due to melanocortin 4 receptor deficiency.