Increased expression of CIS genes. (A) Expression levels of Mn1 were evaluated in mice with Mn1 insertions (N = 4), mice without Mn1 or Evi1 insertions (N = 5), mice with Evi1 insertions but without Mn1 insertions (N = 5), WT spleen (N = 5), and WT BM (N = 5). *P < .03. **P < .01. ns indicates not significant. (B) Expression levels of Evi1 in mice with Evi1 insertions (N = 5), mice without Evi1 insertions (N = 4), WT spleen (N = 5), and WT BM (N = 5). (C) Evaluation of 8 additional CIS (Plag1, Mpl, Kras, Erg, Ift57, Cd47, Vav1, and Gata1) compared with either WT bone marrow (N = 5) or WT spleen (N = 5). Expression of each gene was determined by quantitative RT-PCR and normalized to the 18S ribosomal RNA.