[CANCER RESEARCH 37, 456-459, February 1977] SUMMARY 4-Hydroxycycbophosphamide, phosphanamide mustard, and non-nitrogen mustard are compounds considered as candidates for the biologically active, alkylating metabolite of cyclophosphamide. These compounds were tested for inhibition of chemotaxis in neutraphils from normal human

4-Hydroxycycbophosphamide, phosphanamide mustard, and non-nitrogen mustard are compounds considered as candidates for the biologically active, alkylating metabolite of cyclophosphamide. These compounds were tested for inhibition of chemotaxis in neutraphils from normal human donors. Of those tested, only 4-hydroxycycbaphasphamide caused a significant (p < 0.01) decrease in the chemotactic index. The chemical precursor of 4-hydnoxycycbophos phamide, 4-hydnoperoxycycbaphosphamide, caused a barely significant (p < 0.05) decrease; 4-ketocycbophos phamide had no effect.