Selective suppression of MyH9 protein with siRNA. Human primary T lymphocytes were transfected with Cy3-conjugated control siRNA only or Cy3-conjugated control siRNA plus MyH9 siRNA at a 1:10 ratio and allowed to migrate on ICAM-1/CXCL-12 cover glasses. (A) An overlay of DIC and Cy3 fluorescence images is shown. Bar, 20 μm. (B) Quantification of tail detachment, as determined by the polarization index. The polarization index was measured on Cy3⁺ cells. *, P < 0.0001 for MyH9 siRNA (n = 19) versus control siRNA only. (C) T lymphocyte cell lysates were analyzed for MyH9 and β-actin levels by Western blot. Experiments were repeated on T lymphocyte preparations from three independent donors.