Taxilin Alpha (TXLNa) also known as interleukin-14 (IL-14) is a cytokine that controls the growth and proliferation of both normal and cancerous B cells. TXLNa induces B-cell proliferation, inhibits antibody secretion, and expands selected B-cell subgroups. This interleukin is produced mainly by T cells and certain malignant B cells. Besides, Phosphodiesterase 4D Interacting Protein (PDE4DIP) has been identified as an interactor of TXLNa, thus a binding ELISA assay was conducted to detect the interaction of recombinant mouse TXLNa and recombinant human PDE4DIP. Briefly, TXLNa were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100ul were then transferred to PDE4DIP-coated microtiter wells and incubated for 2h at 37℃. Wells were washed with PBST and incubated for 1h with anti-TXLNa pAb, then aspirated and washed 3 times. After incubation with HRP labelled secondary antibody, wells were aspirated and washed 3 times. With the addition of substrate solution , wells were incubated 15-25 minutes at 37℃. Finally, add 50μL stop solution to the wells and read at 450nm immediately. The binding activity of TXLNa and PDE4DIP was shown in Figure 1, the EC50?for this effect is 0.09ug/mL.