MCL1 and neoplasm: These results presented that it significantly down-regulated the expression of red fluorescence protein in B16F10-RFP cells (down to ~40%); moreover, antitumor assay in vivo displayed that these nanoparticles loading with Mcl-1-specific siRNA (siMcl-1) could be internalized into human KB tumor cells; and demonstrated a cooperative effect which reduced tumor size by 83.4%.