Given the intricate role of CTSB, enolase, and GAL3 enzymes in lung cancer progression and the potential benefits of fisetin, this study aims to explore the effectiveness of a fisetin-loaded nano emulsion (FNE) in attenuating these pathological markers, in vitro, in lung cancer cells, specifically the A549 human lung adenocarcinoma cells. Here, CTSB is linked to lung cancer.