Many circulating immune cells including CD34+ hematopoietic cells, CD4+ and CD8+ lymphocytes, and platelets express the long form of the leptin receptor Ob-Rb (124), as well as toll-like receptor 4 (TLR4) and inflammatory chemokine C-C chemokine ligand 2 (CCL2) receptor, that enable them to crosstalk with cancer and adipose tissue (125). Here, TLR4 is linked to cancer.