Classification and biology of tumour associated stromal cells

Stroma is a fundamental component of the tumour microenvironment whereby it supports malignant cell growth and spreading. It consists of different entities including cells of the immune system, vascular structures and fibroblasts. Much attention has recently been paid to fibroblasts since there is compelling evidence that they orchestrate the recruitment of and educate other cells to promote cancer growth. This review proposes to discuss in detail the nomenclature, origin, and biological functions of the different stromal cells residing in tumours.