One of the salient features common to all malignancies is the role of the habitat, be it the tumor microenvironment or the bone marrow microenvironment, in mediating drug resistance.  These habitats form protective niches by offering sanctuary to malignant cells and are the critical lifeline for maintaining minimal residual disease.  Disruption of this symbiotic partnership between the malignant cells and its environment has proven to be a challenge due to the plasticity of the malignant cells (part of it endowed by the microenvironment) and presence of myriads supportive players (cells and soluble factors).  In lieu of this, the aim of the present Specia Issue is to highlight the numerous facets of the microenvironment that aid in oncogenesis and the various new tools and treatment regimens that can be employed to exploit this process.

The goal for this issue is to bring together studies from diverse oncology field that are using their expertise to solve or shine new light on avenues to overcome microenvironment-mediated drug resistance.  Our objective is to provide a platform for cross-functional team of experts to come together and share their studies and observation with the goal of assisting in bring about a favorable clinical outcome of eradication of malignant cells in its environment.