STAT3 and gastric cancer: In conclusion, we identified an important mechanism in GC: circUBA2 acts as a sponge for miR-144-5p to upregulate the expression level of STC1, which further activates the IL-6/JAK2/STAT3 signaling pathway to promote CSC-like properties and tumour progression in GC and is therefore significantly associated with poor prognosis in GC.