To determine the function of HCAR1 in OS, HCAR1 in MG‐63 and 143‐B cells was stably overexpressed or knocked down via lentiviral infection, as the intervention efficiency was detected by qRT‐ PCR (Figure 2D,E) and Western blotting (Figure 2F,G; Figure S3F,G, Supporting Information). Here, HCAR1 is linked to infection.