Expression of TRK receptors and NTs in patients with AL. (A) Showing the gate for the blast population. Left panel: patient T10 (AML M5). Middle panel: T14 (T-cell ALL). Right panel: patient T78 (AML M1). (B) Top row showing expression of all 3 TRK receptors in the blasts of patient T10. Middle row: patient T14 expressed only TRKB. Bottom row: patient T78 was negative for TRK receptors. (C) BDNF was also expressed in patients T10 (left panel) and T14 (middle panel), but not in patient T78 (right panel). The isotype controls are shown as insets. (D) Constitutive phosphorylation of p145^TRK in primary leukemic cells. Total cell lysates were blotted and probed with an anti-pTRK (E-6) antibody detecting phosphorylated forms of all 3 TRK receptors. The blot was stripped and reprobed with the anti-TRKB (794) antibody. Please see flow cytometry diagrams in Figures S1 and S3 showing expression of TRKs and BDNF in the blasts of the patients not shown here.