For more advanced osteosarcoma patients, the novel treatment options include immune checkpoint inhibitors (PD-1, PD-L1, CTLA4, TIM3 and IDO1) and new druggable targets, such as KIT, ERBB2, VEGF and PDCD1 and others as summarized in Table 4 below. This evidence concerns the gene CTLA4 and osteosarcoma.