AGER and neoplasm: S100A8/A9, a heterodimeric complex present both intracellularly and extracellularly especially in neutrophils and monocytes, by binding to some proteins such as activated leukocyte cell adhesion molecule (ALCAM), melanoma cell adhesion molecule (MCAM) and receptor for advanced glycation end products (RAGE) which are tumor grade dependent, intervenes in the growth, adhesion and degree of invasiveness of CTCs [64].