(NZB X NZW)F1 hybrid female mice were transfused fortnightly with 1 ml of packed buffy-coat-poor syngeneic erythrocytes, beginning at 3--4 months of age, in an effort to suppress erythropoiesis selectively and perhaps limit availabiliity of DNA for immune complex formation. The mean increase in survival was about 8 weeks (P less than 0-05). Repeatedly phlebotomized donor female mice tended to sicken earlier and die at younger ages. This is initial support for the hypothesis that erythroblast DNA may be involved in this SLE-like disease.