Together, our initial data demonstrate the degradation activity of FerroTACs in cellular context for all three considered model systems. The introduction of the ferrocene moiety did not negatively impact the PROTACs' activity and in some cases, even enhanced their potency or selectivity. The retention of activity, especially when the modification is centrally located, suggests that ferrocene incorporation can be tolerated and favourable for PROTAC function. L tubulin protein ratios were normalised to the average of the controls (100%). Data represent the mean values from two biologically independent experiments. B) Representative blot of dose-response profile of HEK293 cells treated with increasing concentrations of AS4 and AS5 for 24 hours. Cells were treated with 0.5% isopropanol, with controls at 1 μ The L tubulin protein