R115777 inhibits HDJ-2 farnesylation in PBMCs from patients with MDS. PBMCs were processed for SDS-PAGE Western immunoblotting with anti-HDJ-2 antibody, as described in “Patients, materials and methods.” BL, D6, D7, D8, and D9 indicate baseline pretreatment levels and days 6, 7, 8, and 9 after initiation of R115777 treatment, respectively. U indicates unprocessed HDJ-2; P, processed HDJ-2.