A global understanding of therapy response and therapy resistance in haematologic malignancies, including multiple myeloma and acute lymphoblastic leukaemia, in which cancerous cells accumulate in the bone marrow, is still lacking. This is due to the complex nature of the bone marrow. Therefore, the goal of SESAHME is to determine the difference of the bone marrow microenvironment in healthy individuals and patients suffering from multiple myeloma and acute lymphoblastic leukaemia. This will help to understand under which conditions cancerous cells can accumulate and proliferate in the bone marrow which could lead to advanced immunotherapy approaches in the future. To achieve this, the objectives of SESAHME are to 1) establish a method that allows to determine the immune microenvironment composition in human formalin-fixed paraffin-embedded samples of the bone marrow, which has the potential for high-throughput screening and being cost effective at the same time; and 2) to use this method to characterise a healthy and dysfunctional bone marrow microenvironment that can contribute to multiple myeloma/acute lymphoblastic leukaemia development and progression. SESAHME will allow the fellow to independently carry out a project which will set the ground to build upon an own, individual research profile to eventually become an independent researcher. Key transferable training will further improve the employability and career prospects of the fellow, as well as increase the fellow’s communication abilities. The host offers a multi-disciplinary environment that is well connected with experts in the field enabling the fellow to develop a new mindset and approaches. The fellow brings international and specialised wet-lab experience that will facilitate knowledge exchange and increase R&I capacity. Finally, SESAHME will increase the global attractiveness of the host via concrete dissemination activities.