E1A promoter effects on ear swelling. Viruses A–C are deleted for E1A and E1B as well as pTP. The data presented for virus A include previously published (Schaack et al., 2004) as well as new data. Virus B is identical to virus A except that the SV40 poly A site was inserted immediately downstream of the E1A promoter. In this and succeeding figures, results are presented for swelling induced 24 h after subdermal injection of BALB/c mouse ears, with background due to injection of buffer alone subtracted. The numbers of ears analyzed were: virus A, 16; virus B, 8; virus C, 11.