Expression of SI-CLP protein in human cell lines. (A) Western blot analysis of total cell lysates using rat mAb 1C11. Endogenous SI-CLP is represented by specific bands corresponding to MW of about 39 kDa and 33 kDa. In stable transfected H1299-SI-CLP cells, the strongest SI-CLP band has a MW of about 40 kDa. None of these bands is recognized by isotype control rat IgG2a and rat IgGs (data not shown). (B) Loading control.