TFEB and infection: Moreover, cell survival assays, performed with the MTS method, indicated that knockdown of TFEB had no significant effect on cell viability at 48 h and 72 h after infection (n = 6, Fig. 5c), suggesting that knock down of TFEB in GC-1 cells was appropriate for further cell migration experiments between 48 h and 72 h after lentiviral infection.