Use of a new class of phosphoinositide-dependent kinase-1 (PDK-1) inhibitors of formula I for inducing apoptosis in unwanted rapidly proliferating cells, for treating, inhibiting, or delaying the onset of cancer, and for preventing restenosis in a subject that has undergone an angioplasty or stent:wherein X is selected from the group consisting of alkyl and haloalkyl Ar is an aryl radical selected from the group consisting of phenyl, biphenyl, naphthyl, anthryl, phenanthryl, and fluorenyl and wherein Ar is optionally substituted with one or more radicals selected from the group consisting of halo, C1-C4 alkyl, C1-C4 haloalkyl, azido, C1-C4 azidoalkyl, aryl, akylaryl, haloaryl, haloalkylaryl, and combinations thereof and R is selected from the group consisting of nitrile, acetonitrile, ethylnitrile, propylnitrile, carboxamide, amidine, tetrazole, oxime, hydrazone, acetamidine, aminoacetamide, guanidine, and urea.