Relatedly, SUVmax has been found to be positively correlated with concentrations of tumour infiltrating lymphocytes in breast tumours, and with expression of the programmed death protein 1 (PD-1) and serum levels of the chemokine CCL18 released by tumour-associated macrophages in non-small cell lung cancers [30–32]. Here, CCL18 is linked to breast neoplasm.