Regarding tumor markers, a significant decrease was detected in CA19-9 levels after collagen treatment (1.04 ± 0.21 vs. 4.61 ± 0.69, p = 0.013) in HCT116 cells, while CEA, CA72-4, and CYFRA 21-1 levels remained unchanged. The gene discussed is CEACAM5; the disease is neoplasm.