As shown in Fig. 3a and b, when we did not treat with doxorubicin (at a dose of zero for doxorubicin in Fig. 3a and b), the knock-down or overexpression of SIRT6 did not influence the proliferation of U2OS and KHOS/NP osteosarcoma cells. The gene discussed is SIRT6; the disease is osteosarcoma.