Editorial: Revisiting the Metastatic Cascade-Putting Myeloid Cells Into Context

In the tumor microenvironment, there is a wide variety of non-tumor cells, including immune cells, which participate in reciprocal interactions with tumor cells to promote the acquisition of critical cancer hallmarks (1, 2). In hematopoiesis, immune cells of the myeloid lineage arise from the common myeloid progenitor, also known as “myeloid stem cell”. Myeloid cells represent a proponent compartment of the tumor microenvironment, and comprise both terminally-differentiated cells (such as macrophages, neutrophils, eosinophils, basophils, mast cells) and more immature or undifferentiated subsets (such as monocytes), among others (3). This Research Topic focuses on novel mechanistic insights on the intricate role of myeloid cells in cancer metastasis and highlights translational and clinical opportunities.