Does combined costimulation blockade plus rapamycin but not cyclosporine produce permanent engraftment?
A theoretical basis for the differing effects of cyclosporine and rapamycin upon the outcome of costimulation blockade is forwarded. Combined use of costimulation blockade and rapamycin may provide a means to bring costimulation blockade into the clinic.
CD44+ 'tumor stem cells' may play a key role in the establishment of permanent HNSCC cell lines, selecting especially robust cell entities that might drive the progression and metastasis of HNSCC. Individual analysis of 'tumor stem cell' markers will be an important tool for innovative therapies and for determining the prognosis of patients with HNSCC.