Concerning the HDAC inhibitor as a supportive drug for resistance to BRAF inhibitors, a combination of a broad-spectrum HDAC inhibitor (e.g., quisinostat) and a pan-CDK inhibitor (e.g., flavopiridol) has been reported to synergistically suppress the proliferation of BRAF inhibitor-resistant human melanoma cells in a xenograft mouse model [32]. The gene discussed is HDAC9; the disease is melanoma.