In this study we: (a) typed the mucosal colon microbiome in CRC patient tumor lesioned tissue (CRC_LT) and CRC unlesioned tissue (CRC_ULT) from surgical resection in lean and overweight/obese CRC patients by 16S rRNA sequencing; (b) compared the CRC-associated microbiomes with those found in mucosal biopsies (from colonoscopy) of healthy lean and overweight/obese subjects; and (c) measured the CCL2 blood levels, as a biomarker of immune inflammation in both healthy and CRC subjects. The gene discussed is CCL2; the disease is neoplasm.