P-Axl is coexpressed with multiple constitutively phosphorylated non-RTKs and serving as a docking site in CLLB cells. (A) Expression of P-Axl is associated with coexpression of various phospho-nonreceptor kinases. CLL B-cell lysates from the same patient cohort as in Figure 1A were examined for the expression of various phosphorylated intracellular kinases shown by Western blot analysis. Actin was used as loading control. (B) P-Axl is physically associated with multiple nonreceptor kinases in CLL B cells. P-Axl was immunoprecipitated from purified CLL B-cell lysates from patients with CLL (n = 8) using a phospho-Axl–specific antibody. The precipitated immunocomplex was examined by Western blot analysis for the presence of various kinases. The IgG heavy chain (IgG HC) was shown for equal loading of the immunocomplex. Expression levels of these kinases in CLL B-cell lysates were also examined (left) for comparison. Actin was used as loading control for the cell lysates. Patients with CLL were assigned arbitrary numbers and are different from the cohort in Figure 1.