UBE2M and infection: We found similar results if we measured the RT activity in the supernatant at day 5 or at day 7 as the primary readout instead of AUC (Fig. S3C and D), and find that at both time points, knockout of UBE2M which was one of the top hits in each of the screens (Fig. 2C and 3F) had the strongest phenotype in the spreading infections.