CD4+ and CD8+ T lymphocytes were isolated from fresh buffy coat derived from 3 healthy donors and were included in ad hoc generated three-dimensional (3D) matrices recapitulating, in vitro, both the physical and stiffness characteristics of the ECM [30] of healthy tissue (hECM) and triple-negative breast cancer (tECM): specifically, two different precursors PEG-FB based solutions were used [31]. This evidence concerns the gene CD4 and triple-negative breast carcinoma.