TGIF1 and Thrombocytosis: Thus, there are 5 genes that showed reduction in expression following let-7b and mir-223 knockdowns that yielded thrombocytosis are tgif1, irf8, tgif1, cebpa, and rorca and one gene, ikzf1 resulted in reduction in expression following let-7b knockdown that yielded thrombocytopenia.