non-small cell lung cancer (NSCLC) remains one of the most mortality solid tumours in the world. The acquisition of resistance to treatments, coupled with the lack of effectiveness of treatment on tumour stem cells (Cancer Stem Cells, CSCs) and immunoevasion mechanisms promulgated by the tumour, are one of the main causes of high mortality. CSCs in NSCLC are strictly recognised by the immunological surveillance system, forming an important mechanism of tumour immune escape, favouring the existence of an immunosuppressive environment which is crucial during tumorigenesis. In addition, the immune cells infiltrating the tumour are also able to modulate the capacity of tumour cells, thereby acquiring stem-like characteristics, further favouring progression, recurrence, metastasis and resistance to treatment. It is therefore necessary to further study the interrelationship between pulmonary CSCs and their immune microenvironment by moving the findings to the search for biomarkers to help improve prognosis. The aim of this work is to study this interrelationship between the immune microenvironment and pulmonary CSCs. To this end, the study shall be carried out in NSCLC cells (cell lines and cultures derived from patient samples) and shall consist of (i) titrating the presence of soluble mediators (cytosines, growth factors, etc.) with immunosuppressive or immuno-regulatory capacity using multiparametric ELISA (Luminex) as supernatant from monolayer cultured cells and in spheres. (ii) analyse the influence of soluble mediators produced by tumo-spheres on different immune cell populations and finally (iii) identify possible mechanisms involved in modulation of immune cells infiltrating tumour cells and CSCs. In conclusion, this work has a clear translational purpose, through the subsequent and future validation of the findings made during this exploratory phase. In addition, the results of this work could lead to new scenarios on therapeutic possibilities leading to the development of modulation of interactions between CSCs and the tumour immune environment, with the aim of eliminating the population of CSCs. Torres Martínez, S. (2017). Characterisation of the Interaction between Madre Tumoral Cell and Inmune microenvironment in non-small cell cancer. http://hdl.handle.net/10251/86114