Patients undergo blood, normal skin, and tumor tissue collection at baseline and periodically during study for pharmacological, biological, and genotyping studies. Blood samples are analyzed by LC/MS/MS assay to assess rapamycin pharmacokinetics (PKs) during courses 1 and 2 and to determine baseline CYP3A4 activity. Samples are also analyzed by genotyping studies to assess CYP3A4 polymorphisms. Pharmacodynamic activity of rapamycin is assessed in peripheral blood mononuclear cells isolated from PK blood samples using a kinase assay to measure S6K activity. Tumor tissue is collected from pretreatment tumor samples obtained at the time of diagnosis or surgery or by biopsy from patients for whom pre-study tumor specimens are not available. Patients undergo skin biopsies at baseline and on day 1 of course 2 to obtain samples of normal skin. Patients also undergo oral mucosa smears at baseline and weekly during course 1. Tumor tissue, normal skin, and oral mucosa samples are assessed by IHC staining of S6K and p-S6K and by RT-PCR for cyclin D1 and p27.