SIRT1 and nasopharyngeal carcinoma: In order to investigate if the viability of the NPC cells are also modulated by SIRTs, we subjected both the Lapatinib resistant 5-8F and sensitive 6-10B NPC cells to treatment with the SIRT1-specific (ie. EX527), SIRT2-specific (ie. AK1 and AGK2) and pan-SIRT (ie. Sirtinol) inhibitors individually for 72 h and their subsequent long-term survival examined by clonogenic assays (Fig. 4a and b).