TAP2 and cervical carcinoma: In addition, the defect in presentation of HPV16 E6 [25-27,40-43] correlates with low level expression of HLA class-I, proteasome subunits low molecular mass protein 2 and 7, and the transporter proteins TAP1 and TAP2 in the cervical carcinoma cell lines, suggesting that presentation of the HPV16 E6 epitope in cervical carcinoma cell lines is limited by mechanisms other than the level of HPV16 E629–38 epitope availability [43].