Fourteen cervical carcinomas containing HPV 16 DNA were analyzed by Southern blot hybridization with probes for HPV 16 E1, E2, E6, and E7 genes. All tumors hybridized with the E7 gene-specific probe while 2 tumors appear to be deleted in the E6 region. In 11 of the 14 tumors, deletions and/or rearrangements were detected in the E1 and E2 regions. Only one of the 14 tumors had a prototype HPV 16 restriction. Our findings that the E7 gene is the most conserved region of HPV 16 in cervical carcinomas suggest it may play a role in the maintenance of the malignant state.