Relative SPRY4-IT1 expression and its clinical significance in gastric cancer tissues. a SPRY4-IT1 expression in matched cancerous tissues and adjacent noncancerous tissues from 61 gastric cancer patients were measured by qRT-PCR. Relative gene expression determinations were made with the comparative delta CT normalized to GAPDH expression (P = 0.001). b According to the median ratio of relative SPRY4-IT1 expression (0.535) in tumor tissues, SPRY4-IT1 expression was classified into two groups: relative high-SPRY4-IT1 group (n = 30, red column) and relative low- SPRY4-IT1 group (n = 31, blue column). Data was presented as fold-change in tumor tissues relative to normal tissues (P = 0.001). c, d Kaplan–Meier overall survival and disease-free survival curves according to SPRY4-IT1 expression level. Patients with decreased SPRY4-IT1 expression (n = 31) showed reduced survival times compared with patients with high level of SPRY4-IT1 expression (n = 31) (P = 0.001 or 0.002, log-rank test).