TGFB1 and neoplasm: Therefore, a cell mixture of the green 5-chloromethylfluorescein diacetate (CMFDA)-labeled-TGF-β1-induced (10 ng/mL) cells and the untreated cells (0 ng/mL) was seeded on the chitosan substrate in different proportions (1:3, 1:1, and 3:1) to simulate the heterogeneous tumor population (Figure 9A).