90). Our research group has already demonstrated that different cervical cancer cell lines express ectonucleotidase members at different levels and show different hydrolysis patterns of adenine nucleotides (Ref. 91). Whereas SiHa (HPV+) and HeLa (HPV+) cancer cell lines presented similar levels of CD73 expression and AMP hydrolysis, in C33A (HPV-) cells, the expression of this gene and its enzymatic activity were almost undetectable (Ref. 91). This evidence concerns the gene NT5E and cancer.