Ribozyme Rzd inhibits synthesis of mRNAs for TNF and GM-CSF. JMML cells were incubated alone (none), with only liposomes (DOTAP), or with the ribozymes Rzd or Rzdm for 48 hours before the cells were collected and total RNA was extracted. Cytokine mRNA levels were then estimated with an RNAse protection assay. Results are expressed relative to the mRNA level of the internal GAPDH standard, and representative data from 1 of the 3 patients are shown. (▪) GM-CSF; (□) TNF; (▧) G-CSF.