The present CTT number starts with a review article by Dr. Elezov and Kudryavtsev concerns modern knowledge on expression and regulation of PD-1 receptor and its ligand PLD-1, like as on their role in diagnostics and prediction of cancer treatment with immune checkpoint inhibitors.

An original study by Dr. Popova et al. describes a representative cohort of patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). The authors have tested the pre-transplant fungal infection in this group, and have found that prior invasive fungal disease did not produce a significant impact on transplant-related complications and overall survival.

A single-center study by Dr. T. Rudakova et al. presents original data on their experience with of thrombopoietin receptor agonists used in the patients with poor graft function after allo-HSCT. The workers have observed good clinical response in sufficient part of this group and safety of long-term administration of TPO receptor agonists.

The interdisciplinary study performed by Dr E. Kulagin et al. concerned pre-existing respiratory disorders as a possible factor of adverse effects upon posttransplant complications and survival of HSCT patients. The pulmonary comorbidities in children and adults before allo-HSCT proved to be a significant independent risk factor with respect to posttransplant disorders.

A comprehensive article by Prof. Mamaev et al. provides additional evidence on diagnostic utility of BAALC gene overexpression in acute myeloid leukemia. Combined overexpression of BAALC and WT1 genes may be used for regular post-transplant monitoring of relapses in this disorder.

A pilot study of mesenchymal stem cell infusions for treatment of ulcerative colitis by Prof. Galina Fedotovskikh et al. is focused, mainly, on morphological correlates of intestinal damage several months after standard and MSC-supplemented therapy. The article should elicit some discussions, due to small number of cases and the issues of morphological criteria used.

Two interesting clinical cases are presented by A. Smirnova et al. They illustrate a striking clinical effect in extramedullary relapsed/refractory B-acute lymphoblastic leukemia obtained with Inotuzumab after failure of treatment with Blinotumomab, thus showing differential target effects when using these antibodies.

The experimental section is opened by an article (Orlova et al.), concerning synthetic poly-L, L-lactide matrices which, being implanted with allogeneic mesenchymal stem cells, are able to promote restoration of the urinary bladder defects in the animals.

An article by Parfenenkova et al. deals with exosomes, the nanoparticles derived from tumor cells which, as shown in the in vitro experiments, may transfer oncogenic transcripts to the cultured normal mesenchymal cells from human hematopoietic microenvironment.

The CTT issue is closing with a review of actual studies reported at the XXIV Congress of European Hematology Association. The article covers new results and developments in hematopoietic stem cell transplantation, application of novel targeted drugs, including immune checkpoint inhibitors, in lymphoma treatment, CAR-T cell therapy an acute lymphoblastic leukemia, new approaches to treatment of myeloid neoplasias, as well as ensuing infectious problems and antibacterial treatment in these conditions.