CYCS and acute promyelocytic leukemia: In the present study, we report cytochrome C delivery to Acute Promyelocytic Leukemia (APL) NB4 cell line by means of a chimeric archeal-human ferritin (HumFt) that combines the unique salt mediated association/dissociation equilibrium of Archaeoglobus fulgidus ferritin with the human H ferritin ability of recognizing CD71 receptor.