For instance, in osteosarcoma, circ_0004674 can sponge miR-142-5p, upregulate the anti-apoptotic protein MCL1 of the Bcl-2 family, leading to osteosarcoma progression and doxorubicin resistance.590 In laryngeal squamous cell carcinoma (LSCC), circPARD3 sponges miR-145-5p to activate the PRKCI-Akt-mTOR pathway and inhibit autophagy, promoting tumor cell proliferation, migration, invasion, and cisplatin resistance.591 Moreover, circRNAs regulate the sensitivity to chemotherapy drugs by directly interacting with proteins. This evidence concerns the gene MTOR and osteosarcoma.