We next explored the mechanism of anticancer activity for the two most potent cancer‐selective ACPs: DHK and EEK (IC50 = 1.0 ± 0.2 μm), and their non‐selective D‐enantiomers: d‐DHK and d‐EEK (IC50 = 0.3 ± 0.1 μm). DHK, d‐DHK, and d‐EEK are haemolytic (HC50 = 14 ± 5 μm), while EEK causes only minimal human red blood cell lysis below 90 μm (Figure S8a, Supporting Information). The gene discussed is EPHA8; the disease is cancer.