TLR9 and CD4+/CD56+ hematodermic neoplasm: Quantitative RT-PCR confirmed that RUNX2 KD cells had significantly lower expression levels of pDC-signature genes, such as TCF4, TLR7, TLR9, and IL-3RA, than control cells (Fig. 3c), indicating that RUNX2 maintained pDC-signature gene expression in BPDCN cells.