Abstract: Disclosed herein are chimeric fusion proteins comprising a c-Myc inhibitor fused to genetically modified Pseudomonas Aeroginosa Exotoxin A (‘tPE’), said fusion proteins being capable of penetrating a nucleus of a cell and inhibiting c-Myc activity within the nucleus. Also disclosed herein are pharmaceutical compositions comprising chimeric fusion proteins, methods of delivering, methods of preparing, methods of treating and uses of chimeric fusion proteins.