“…The question, whether chimerism status is somehow connected to the incipient relapse, or if it could be taken as an indicator of an impending relapse, has been disputed intensively during the last two decades. Several research groups found correlation between mixed chimerism (MC) and AML relapse (Lawler, Humphries & McCann, 1991;Bader et al, 1997Bader et al, , 1998, while such relationship was disapproved by others (Schattenberg et al, 1989;Roy et al, 1990;Bertheas et al, 1991;van Leeuwen et al, 1993van Leeuwen et al, , 1994Suttorp et al, 1993;Choi et al, 2000;Schaap et al, 2002). This controversy can be partially explained in context of dynamic process of MC: whereas reappearance or increase in autologous hematopoiesis is related with the impending AML relapse, stable MC is not (Formá nková et al, 2000(Formá nková et al, , 2003Wä sch et al, 2000;Mattsson et al, 2001;Pé rez-Simó n et al, 2002;Schaap et al, 2002;Barrios et al, 2003;Ferná ndez-Avilé s et al, 2003;Lamba et al, 2004;Scheffold et al, 2004;Huisman et al, 2007).…”