MYC and infection: Wild-type 38B9 cells treated with control supernatant died very quickly after application of selection pressure (Figure 4A), whereas 38B9 cells infected with retroviral supernatants derived from pBMN-I-EGFP-T2A-Puro or pBMN-I-EGFP-T2A-Puro Myc showed both successful infection and selection, as EGFP-positive cells were visible after infection and presumably uninfected EGFP-negative cells disappeared after application of Puromycin selection (Figure 4B,C).