MYC and lentivirus infection: In fact, we have tried to get direct evidence to confirm the c-Myc-dependent tumour suppressive role of ELL through establishing stable cell lines using three-round lentivirus infections based on the established stable cell lines with endogenous c-Myc knockdown plus overexpression of wild-type c-Myc (c-Myc-shRNA resistant) or c-Myc(4K/R) mutant.