RNF40 and osteosarcoma: In addition, deficiency of ALKBH5‐mediated m6A modification in osteosarcoma causes an increase expression of histone deubiquitinase USP22 and ubiquitin ligase RNF40, which inhibits histone H2AK199 monoubiquitination, induces the expression of genes related to DNA repair, and promotes the progression of osteosarcoma.52