101), which have tumour-initiating ability and play a critical role in tumour metastasis, relapse and chemoresistance (Ref. 102). Our results evidenced a reduction in CD73 expression and enzymatic activity in cervical spheres when compared to monolayers (Ref. 99). Interestingly, our in silico analyses have supported our in vitro results, showing that three-dimensional spheres derived from cervical, thyroid and breast cancer presented decreased expression of CD73, when compared to their adherent counterparts (Ref. 99). This evidence concerns the gene NT5E and breast cancer.