As an indicator of viral replication of Delta24-RGD in GL261 cells in vitro, viral E1A levels were determined by qPCR between 24–96 hr post-infection at MOI 100, showing an approximate 100-fold increase in E1A copies in the cells and a 10-fold increase in the supernatants between 48 and 96 hr (figure 1B). This evidence concerns the gene DHTKD1 and infection.