Coat depigmentation in mice immunized with hTRP-2. Groups of 12-19 C57BL/6 mice (wild type) and mice of the same background deficient in IL4 (IL4^-/-) or IFN-gamma (IFN-gamma^-/-) were immunized with hTRP-2 and observed for the appearance of white hair. (A) The appearance of representative mice observed for 70 days after immunization- left to right: wild type, IL4^-/-, IFN-gamma^-/-. (B) The number of depigmented abdominal quadrants measured over time. IL4^-/- mice depigmented most quickly, but wild type animals eventually achieved the same degree of depigmentation.