Confocal microscopy for fluorescent in situ hybridization (FISH) showed that FMR1-AS1 located primarily in the cytoplasm (Fig. 2b), which was confirmed by qPCR in nuclear/cytoplasm fractionation (Fig. 2c), may exert its biological function in the cytoplasm of ESCC cells. Here, FMR1-AS1 is linked to esophageal squamous cell carcinoma.