Tipifarnib treatment results in inhibition of HDJ-2 protein farnesylation in multiple myeloma cells. Multiple myeloma cells were prepared and processed for SDS-PAGE immunoblotting with anti-HDJ-2 antibody as described in “Materials and methods.” B and T designate baseline pretreatment levels and levels during the 3rd week of tipifarnib treatment, respectively. U and P designate unprocessed and processed HDJ-2, respectively.