Despite multiple markers like α-smooth muscle actin (α-SMA/ACTA2) (Lazard et al., 1993), fibroblast activation protein (FAP) (Kraman et al., 2010), and periostin (POSTN) (Komura et al., 2024) have been identified in colon cancer, accurately defining cancer-associated fibroblasts remain challenging due to their marked heterogeneity. The gene discussed is POSTN; the disease is cancer.