In this current study, exosomal miR-15b-3p (exo-miR-15b-3p) was found to be released by BGC-823 cells, promoting GC progression and the malignant transformation of GES-1 (normal gastric mucosa epithelium cells), by regulating the DYNLT1/Caspase-3/Caspase-9 axis. Here, CASP9 is linked to gastric cancer.