We have mapped using the RNA PCR the viral-cellular junctions of HPV16 viral-cellular cotranscripts expressed in CaSki cells and a cervical carcinoma to nt 3728 and 881, respectively. Both junctions were located within the E1-E2 region. Examination of the cellular sequences of the cotranscripts showed the presence of a polyadenylation signal in each of the transcripts. In CaSki cells and in the cervical carcinoma transcripts derived from the full-length early region including the E2 transcript were also detected. Our results suggest that the utilization of a cellular polyadenylation site could be important in the development of cancer by HPV.