RB1 and cancer: The cytotoxicity of tested compoundswas evaluated in three basal cell carcinoma cell line models, as basalcell carcinoma is the most common form of skin cancer and the mostfrequently occurring form of cancer overall.25,26 The complexes revealed a higher phototoxicity relative to free RB(Figure 4A and Figure S1), and this trend was maintained inall tested cell lines: RB in complex with PPI dendrimers was moretoxic than RB in complex with PAMAM dendrimers, regardless of thegeneration.