Beyond the extracellular matrix, there is the infiltration of two particular types of cells: the former are the cells of the immune system, which are recruited by inflammatory stimuli induced by hypoxia and necrosis, caused by the low oxygen in the tumor microenvironment and which can play both a pro- and anti-tumor role; the latter are the tumor-associated endothelial cells, which are involved in the structural processes of neovascularization, due to a lower production of intercellular adhesion molecule 1 and 2 (ICAM1 and ICAM2). Here, ICAM1 is linked to neoplasm.