FIG. 1.

E4orf3 cooperates with E1A to promote focus formation. (A) Primary BRK cells were transfected with the indicated amounts of plasmids (micrograms of DNA), and morphologically transformed colonies were scored 4 weeks after transfection. Focus-forming activity is represented as a percentage of pCMV-E1A activity. The mean and standard deviation are presented for three independent experiments. The average number of foci for pCMV-E1A was 5. (B) Representative crystal violet-stained plates showing foci from transfections with plasmids encoding Ad5 E1A, E4orf3, and E4orf6.