DDIT4 and gastric cancer: Upon stress induction, including oxidative stress, endoplasmic reticulum stress, hypoxia and starvation [11, 13–15], DDIT4 inhibits mTOR signalling by stabilizing the tuberous sclerosis complex (TSC1-TSC2) [16, 17], DDIT4 is aberrantly expressed at low levels in multiple tumours, including gastric cancer [18], breast cancer [19], glioma [20] and other tumours [21–23] The antisense transcript of DDIT4 encodes the lncRNA DDIT4-AS1, which has a length of 847 bp and consists of two exons.