The Ship and C/ebpβ down-regulation in the miR-155 transgenic splenocytes compared with the wild-type splenocytes occurs mainly in the B-cell precursors rather than in the mature B cells. (A-B) Western blots on proteins extracted from total splenocytes show the lack of expression of SHIP-1 (A) and C/EBPβ (B) in the leukemic compared with the wild-types. Note: The samples marked “T” are 2 T-cell leukemias arisen in the miR-155 transgenic mice.