Fluorescenceimaging confirmed efficient intracellular delivery of FAM-labeledsiRNA into T98G human glioblastoma (GBM) cells exclusively with G3-CYS,correlating with a marked reduction to 15–25% of control levelsin target protein expression of p42-MAPK, Rheb, and MGMT. The gene discussed is MGMT; the disease is glioblastoma.