CXCR4 and psoriasis: However, we also noted in the literature some success of gene silencing obtained with low concentration of siRNA (<100nM) on immune cells in vitro: For example, Lipid-Substituted Polyethylenimines were used on THP-1 Acute Myeloid Leukemia cells to silence CXCR4 with 25 to 50 nM of siRNA [102], PEG-PLL-PLLeu micelleplex were used with 100nM siRNA to silence c-Rel in Bone marrow derived dendritic cells (BMDC) and RAW264.7 macrophages to treat Psoriasis [22].