Ciliary Neurotrophic Factor (CNTF) is a multifunctional cytokine primarily known for neurotrophic roles. It supports survival and differentiation of ciliary ganglion neurons and other neuronal populations. Beyond neurotrophy, it aids neuroprotection by inhibiting neuronal apoptosis, promoting axonal regeneration, and modulating neuroinflammation, showing potential in treating neurodegenerative disorders.?To test the effect of CNTF on cell proliferation, TF-1 cells were seeded into triplicate wells of 96-well plates and allowed to attach, replaced with various concentrations of recombinant human CNTF. After incubated for 72h, cells were observed by inverted microscope and cell proliferation was measured by Cell Counting Kit-8 (CCK-8). Briefly, 10 μl of CCK-8 solution was added to each well of the plate, then the absorbance at 450 nm was measured using a microplate reader after incubating the plate for 1-4 hours at 37 ℃. Cell viability was assessed by CCK-8 assay after incubation with recombinant human CNTF for 72h. The result was shown in Figure 1. It was obvious that CNTF significantly increased cell viability of TF-1 cells. The ED50 of recombinant human CNTF is 4.82 μg/ml.