STAT3 and dry eye syndrome: To further confirm the effect of the calcium‐dependent PI3K‐AKT‐STAT3 signalling pathway on the polarization of KCs, a PI3K inhibitor (IPI‐549), an AKT activity inhibitor (GSK2141795) and a STAT3 phosphorylation inhibitor (Stattic) were all used to inhibit PI3K and the phosphorylation of AKT and STAT3, respectively.