The ongoing issue of CTT opens with a review by Nouran Sabbagh and Axel R. Zander which deals with feasibility and relative efficiency of diff erent hematopoietic transplantation options and probable applications of CAR-T cells in treatment of multiple myeloma patients. In particular, various combinations of tandem hematopoietic transplants and donor lymphocyte infusions are discussed. A review article by Dr. Goloshchapov et al. concerns multiple factors infl uencing human gut microbiome in hematopoietic stem cell transplantation (HSCT), and prospects for fecal microbiota transplantation which now becomes a highly discutable topic. Special attention is drawn to eff ects of intensive therapy upon the intestinal microbiota parameters which may be of suffi cient prognostic value. An original clinical report by Dr. Ivan Moiseev et al. deals with risks of graft -versus-host disease factors in HSCT which arise with different modes of posttransplant immunosuppression. In case of cyclophosphamide-based treatment, cytomegalovirus seropositivity proved to be the major risk factor of GVHD, unlike several other risk factors found with conventional GVHD prophylaxis. A clinical report presented by Dr. Maxim Kucher et al. concerns the intensively studied effect of ABO and Rh- mismatch for the HSCT patients’ survival and subsequent complications. Th e study confi rmed common results on major ABO-incompatibility in the donor-recipient pairs and showed the Rh status (especially, ddccee constellation) to be a negative factor for the 1-year survival aft er HSCT. The available genetic markers of minimal residual disease, e.g., based on the Ig gene rearrangements, proved to be rather sensitive in relapse prediction and risk grouping among the children who underwent HSCT for acute lymphoblastic leukemia, as shown by Viktoria Lavrinenko et al. from the Minsk Center of Pediatric Oncology. Th is is a good example of clinical and laboratory consensus with valuable clinical outcome. An interesting clinical case was described by Dr. Omar Hamdy et al., who dealt with a kidney recipient who developed multiple cancers within several years of convential immunosuppressive therapy. In future, the DNA samples from such cases should be accumulated, requiring deep genetic studies searching for appropriate tumor risk genes. Experimental studies in this issue are presented by a timely report by Prof. Sergej Ulitovskiy et al. in rabbit model of bone injury treated with porous chitosan-based fi lling material which seems to be a biocompatible, bioinert, and bioresorbable matrix for local bone regeneration and fi brous replacement within 3-6 months post-injury. A small, but useful laboratory study by Dr. Oleg Glotov et al. aimed to compare the results of high-resolution HLA testing obtained by conventional Sanger method, and modern NGS-based assay. Th e data showed essential concordance, and a trend for lowering the NGS costs with increasing introduction of this approach in routine practice of Russian HLA-typing laboratories. Th e short report by Tatyana Parkhomenko et al. deals with a rarely used approach to in vitro testing of growth factors, i.e., mitochondria-mediated mechanisms of erythropoietin action upon lymhoid cells. At the current level of research, this technique may be used for fl ow cytometric screening of novel drugs and substances used in oncohematology.