CD8A and neoplasm: Other serum markers such as absolute lymphocyte count, leukocyte-to-lymphocyte ratio, monocyte count, eosinophil count, lactate dehydrogenase (LDH), circulating IgM-Rheumatoid, and circulating tumor DNA (ctDNA), as well as the presence of particular circulating cellular populations (like CD14+ CD16- HLA-DRhigh monocytes [141] or PD-1+ Ki-67+ CD8+ T-cells [142]), have been investigated as predictors [137,138,139,140].