Inclusion Criteria:  The patient who will receive a conditioning regimen including melphalan as a part of hematopoietic stem cell transplantation (HSCT). Age is below 19 at the time of diagnosis of a disease which is HSCT indication Written Study Informed consent and/or assent from the patient, parent, or guardian  Exclusion Criteria:  Female patients who are pregnant or breast feeding Study treatment would deteriorate patient's disease. The patient may have problems with study participation due to a psychotic disorder. Any condition that would, in the Investigator's judgement, interfere with participation in the study