RHO and neoplasm: Each protein domain contributed unique bioactivity features to the resulting construct: (1) SST provides cell‐type selectivity for cells overexpressing SSTR2; (2) multiplication of the SST targeting groups enhanced cellular uptake via the multivalency effect; and (3) potent enzyme activity of the only known selective Rho inhibitor, bacterial toxin C3, that is (4) released upon a pH stimulus in acidic cellular compartments to significantly affect tumor angiogenesis by preventing blood vessel formation and regulation of capillary formation.