The expression level of TTTY15, miR-98-5p, and cyclin D2 (CCND2) were evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot assay using tumor and non-tumor tissues collected from 30 patients with gastric cancer, gastric cancer cell lines (AGS, SNU-5, and NCI-N87), and the normal gastric epithelial cell line GES-1. This evidence concerns the gene CCND2 and gastric cancer.