 - iii Cytogenetic relapse defined as: the appearance in one or more metaphases from bone marrow or peripheral blood cells of either a non-constitutional cytogenetic abnormality identified in at least one cytogenetic study performed prior to transplant or a new abnormality known to be associated with leukemia; for CML an increase in the number of Ph metaphases from bone marrow or peripheral blood between two consecutive samples after engraftment, or; an increase in the percentage of BCRABL cells by fluorescence in situ hybridization FISH between two consecutive samples after engraftment 