To verify if the same chemosensitizing effects were maintained in 3D-cultures, a model closer to the in vivo tumor biology and characterized by higher Pgp expression and doxorubicin resistance compared to 2D-cultures [32], we produced 3D-cultures of T47D cells, which were Pgp-negative (Fig. 1a) and doxorubicin-sensitive (Fig. 2b) cells when grown bi-dimensionally. This evidence concerns the gene PGP and neoplasm.