HDAC9 and neoplasm: It has been found that HDAC inhibitors induced apoptosis in particular types of NSCLC cells when combined with irreversible EGFR-TKI or pemetrexed [29, 35], However, the individual tumour cells have heterogenous responses to HDACi induced apoptosis [38], and there’s no significant improvements exit in the overall outcome for advanced NSCLC patients treated with HDACi and erlotinib [13].