In addition, Insua et al. used circulating tumor cells (CTCs) in patients with metastatic colorectal cancer to measure the levels of mRNA from a panel of six genes (GAPDH, CLU, VIL1, TIMP1, LOXL3, and ZEB2), where they identified that this approach effectively allowed the identification of patients who did not respond to first-line chemotherapy and had worse progression-free survival and overall survival rates [124,125]. Here, TIMP1 is linked to metastatic colorectal cancer.