Ability to reject third-party hearts. Hearts from third-party C3H/HeJ newborn mice (H2^k) were transplanted into pouches created in the pinnae of BALB/c (H2^d) recipients of C57BL/6 (H2b) T-cell-depleted bone marrow 14 days after bone marrow transplantation. Graft survival was assessed daily by evaluation of the presence or absence of heart contractions. The hearts were followed for 60 days after heart transplantation. The comparisons were among all different groups. The results were pooled from 2 independent experiments. TCD BM indicates T-cell-depleted bone marrow.