Expression of JAB in M1 and 3T3 transformants. Parental M1 or NIH-3T3 cells were stimulated without (N.S.) or with 1,000 IU/mL IFN-γ, 1,000 IU/mL IFN-β, or 10 ng/mL LIF for 12 hours, and then the total RNA was isolated. Total RNA was also isolated from untreated M1 transformant expressing JAB (M1-JAB), NIH-3T3 transformant (NIH3T3-JAB), and CTLL2 cells. The RNAs were subjected to Northern blotting with probe for JAB and control G3PDH. The arrowheads indicate JAB message derived from transfected cDNA in pLXSN (LXSN-JAB) in NIH3T3-JAB transformant, that in pcDNA3 (pcDNA3-JAB) in M1-JAB transformant, and endogenous JAB (end-JAB).