STAT3 and ovarian carcinoma: Figure 4(D) further indicated that miR-146b overexpression reduced the levels of total STAT3 in the ovarian cancer cell lines. We then examined the level of phosphorylated STAT3 protein and found that tyrosine phosphorylation and serine phosphorylation of STAT3 were both significantly decreased after miR-146b overexpression in the ovarian cancer cell line (Figure 4(E)).