The silencing of ERα in the P53+ U2OS cells induced sensitivity to doxorubicin treatment that suppressed colony formation (48.9 ± 10.51%), but this effect was not observed in the P53− SAOS cells (70.3 ± 16.69%) (Figure 4A,B), indicating that targeting ERα enhanced the tumor suppression effect of doxorubicin. Here, ESR1 is linked to neoplasm.