Most of the tested human cancer cell lines from various origins (HT1080: fibrosarcoma, U2OS, SAOS-2: osteosarcoma, A549, H1299: lung cancer, HeLa: cervical cancer, Huh7, SNU475, Hep3B: hepatocellular carcinoma, MDA-MB-231: breast cancer, SW480: colorectal cancer) had higher levels of PSMD1 protein compared with that of normal human retinal pigment epithelial cells, small airway epithelial cells, and normal fibroblasts (Wi38 and IMR90) (Fig. 1d). Here, PSMD1 is linked to osteosarcoma.