Viral replication of Surv.m- CRA and cytotoxicity against sorted FGFR3- positive and FGFR3- negative cells. Sorted FGFR3-positive and FGFR3-negative cells were infected with Surv.m-CRA, Ad.dE1.3, or no virus (none) at an MOI of 1. The cells were observed under phase-contrast and fluorescence microscopy 1, 3, and 5 days after infection. Representative phase-contrast (upper) and fluorescence (lower) images are shown at 50× magnification. In the case of no infection (none), FGFR3-positive cells proliferated more rapidly than FGFR3-negative cells after 3 and 5 days. By contrast, the proportion of remaining cells 5 days after Surv.m-CRA infection was lower in FGFR3-positive than in FGFR3-negative cells. These results suggest that Surv.m-CRA exhibited more efficient replication in and cytotoxicity against sorted FGFR3-positive than FGFR3-negative cells.