We conducted α2M–RG internalization assays using seven cell lines derived from different origins: HEK293 (embryonic kidney), HeLa (cervical cancer), A549 (lung cancer), U2OS (osteosarcoma), Huh7 (liver carcinoma), HCT116 (colon cancer), and T98G (glioblastoma). Here, A2M is linked to osteosarcoma.