Since results from the in vitro study produced a hint that the modulatory effect of HTATIP2 knockdown on the in vitro behavior of A549 cells might be associated with HIF2α-mediated tumor adaptation to hypoxia, a subcutaneous tumor xenograft model was employed to further investigate the effect of the absent HTATIP2 expression on the phenotypic behavior of growing tumors. Here, EPAS1 is linked to neoplasm.