TIE1 and ovarian hyperstimulation syndrome: Similarly, the Tie1 mRNA level was significantly higher in granulosa cells from OHSS patients than in cells from controls (Fig. 1g), protein expression levels also increased (Fig. 1h), and its level increased 1.5-fold in granulosa cells from controls cultured in the presence of hCG for 24 h compared to untreated cells (Fig. 1i, j).