Here we assess the relation between abdominal subcutaneous AT (SCAT) CTSL1 and CTSB gene expression (qRT-PCR), body composition and tissue-specific insulin resistance in 77 overweight/obese (BMI: 225.6–38.6 kg/m2) well phenotyped men and women (61 M/16 F). The gene discussed is CTSB; the disease is Insulin resistance.