Leukemias initiated by Kras^D12/G37 and Kras^D12/G64 expression demonstrate distinct signaling profiles. (A) Immunoblot of T-ALL cell lines under basal (B) and starved (S) conditions. Two control T-ALL cell lines with WT Kras (C) from a retroviral insertional mutagenesis screen¹¹  were included. Ten cell lines were generated from independent leukemias induced by either Kras^D12/G37 (E1-E4) or Kras^D12/G64 (Y1-Y6). (B) Ras was immunoprecipitated from cell lines E1-E4 and then probed with an antibody that recognizes the D12 substitution. (C) quantitative PCR analysis of Kras expression in T-ALL cell lines compared with WT thymus.