PCNA and cancer: Our study indicates the potential of cyclosaplin, a cyclic octapeptide as an anti-cancer agent against breast cancer, however further experimental studies demonstrating an alteration in proliferation (cyclin B1, E2F1, Ki-67, and proliferating cell nuclear antigen), angiogenesis (VEGFA), and apoptosis markers (Caspase 3, Bax) is required in the 3D silk tumor model.