RHOA is a recurrently mutated gene in diffuse-type gastric cancer, whose molecular influence in gastric cancer has not been well uncovered. We aimed to clarify the contribution of RHOA to pro-oncogenesis to improve the understanding of the role of RHOA as a therapeutic target. We performed microarray analysis after RHOA knockdown for HGC-27, AGS, CCK-81, and SW948. Overall design: To investigate the effects of mutant and wild-type RHOA functions, microarray analysis was performed on the following cell lines in which RHOA was knocked down using RNA interference; HGC-27 which harbored wild-type RHOA, AGS which harbored heterozygous RHOA^p.E64del, CCK-81 which harbored trans-compound heterozygous RHOA^p.R5Q and RHOA^p.Y42C, and SW948 which harbored heterozygous RHOA^p.G17E. The data were normalized to the cells underwent RNA interference using negative control RNA. The experiments were performed twice.