By integrating RNA-seq and whole-exome sequencing data, we found a significantly increased CTNNB1 expression in GCT cases with somatic protein-altering mutations in FAT2 or FAT3 genes compared to GCT cases without such mutations (Mann–Whitney U test, P = 0.001; Supplementary Fig. 1). The gene discussed is CTNNB1; the disease is granular cell tumor.