EPHA2 and esophageal squamous cell carcinoma: Moreover, IHC staining confirmed that the level of EphA2 was increased in PT positive ESCC clinical samples and in the tumors of PDX G5824 compared to that in PT negative ESCC clinical samples and in the tumors of PDX G5835, confirming the finding that PLEKHA1-TACC2 promoted EphA2 protein expression in vivo (Fig. 2G, H).