STEAP2 expression in osteosarcoma, osteofibrous dysplasia, and paratumoral tissues was evaluated using IHC, which revealed that STEAP2 was overexpressed in most osteosarcoma tissues (Figure 1 a and b) but showed a low expression in osteofibrous dysplasia (Figure 1c) and paratumoral tissues (Figure 1d). The gene discussed is STEAP2; the disease is osteosarcoma.