Intradermal vaccination via gene gun efficiently delivers DNA vaccines into dendritic cells (DCs) of the skin, resulting in the activation and priming of antigen-specific T cells in vivo. In the context of DNA vaccines, we previously used the gene gun approach to test several intracellular targeting strategies that are able to route a model antigen, such as the human papillomavirus type-16 (HPV-16) E7, to desired subcellular compartments in order to enhance antigen processing and presentation to T cells. These strategies include the use of the sorting signal of lysosome-associated membrane protein (LAMP-1), Mycobacterium tuberculosis heat-shock protein 70 (HSP70), calreticulin (CRT) and the translocation domain (dII) of Pseudomonas aeruginosa exotoxin A (ETA). Vaccination with DNA vaccines encoding E7 antigen linked to any of these molecules all led to a significant enhancement of E7-specific CD8(+) T-cell immune responses and strong antitumor effects against an E7-expressing tumor, TC-1. However, we were interested in identifying the most potent DNA vaccine for our future clinical trials. Thus, we performed a series of experiments to directly compare the potency of the various DNA vaccines. Among the DNA vaccines we tested, we found that vaccination with pcDNA3-CRT/E7 generated the highest number of E7-specific CD8(+) T cells and potent long-term protection and treatment effects against E7-expressing tumors in mice. Interestingly, we observed that pcDNA3-CRT/E7 is also capable of protecting against an E7-expressing tumor with downregulated MHC class I expression, a common feature associated with most HPV-associated cervical cancers. Our data suggest that the DNA vaccine linking CRT to E7 (CRT/E7) may be a suitable candidate for human trials for the control of HPV infections and HPV-associated lesions.