FOXP3 and chronic myelogenous leukemia, BCR-ABL1 positive: Tnfrsf4 could not be detected on the surface of CD8+ T cells, L-Gr-1+ cells, or LSCs, while a substantial fraction of CD4+Foxp3+ Tregs and a minor fraction of CD4+Foxp3– T cells expressed Tnfrsf4 in the BM of CML mice (Figure 7, A and B).