Previous studies have reported that deletions or mutations in the RTD did not affect virus replication or accumulation in initially infected cells or at the cell level in systemically infected tissue whether the inoculum was 35S promoter-driven virus or an in-vitro transcript, but the number of infection foci in systemically infected tissues were reduced [11, 18, 19, 21, 62]. The gene discussed is REN; the disease is infection.