GCP‐2‐silenced replicative senescent fibroblasts (Rep Sen FB, GCP‐2KDN), following co‐injection with A375 melanoma cells (which were silenced for GCP‐2 and ENA‐78), resulted in significantly smaller tumors, whereas ENA‐78‐silenced senescent fibroblasts (Rep Sen FB, ENA‐78KDN) only showed a tendency towards smaller tumors (Figure 3A–C). The gene discussed is CXCL6; the disease is melanoma.