VGF (nerve growth factor inducible) is a secretory polypeptide precursor belonging to the granin/secretogranin family, selectively expressed in neuronal and neuroendocrine cells. It promotes cell proliferation, survival, and migration, while inhibiting apoptosis in neurons and multiple cancer cell types. VGF drives oncogenic signaling, enhances therapy resistance, and facilitates epithelial–mesenchymal transition. Its proteolytic products mediate neurogenesis, energy homeostasis, and tumor progression, positioning VGF as a key regulator in neural function and cancer pathogenesis.To test the effect of VGF on cell apoptosis, A549 cells were seeded into triplicate wells of 96-well plates and allowed to attach, replaced with various concentrations of recombinant human VGF. After incubated for 48 hours,?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 (Cell Counting Kit-8 ) assay after incubation with recombinant human VGF for 48 hours. The result was shown in Figure 1. It was obvious that VGF significantly decreased cell viability of A549 cells.The ED50 of recombinant human VGF is 230 ng/mL.