CD14 and lung cancer: The median proportion of all PB monocytes in lung cancer patients was 7.1% (Q range: 5.9–8.6), vs. healthy donors: 6.4 (Q range: 4.4–7.5) There are three types of monocytes in PB: the classical monocytes with high expression of the CD14 cell surface receptor and no CD16 expression (CD14++CD16-), the non-classical monocytes with low/negative level of CD14 expression and co-expression of the CD16 receptor (CD14-/+CD16++) and the intermediate monocytes with expression of CD14 and expression of CD16 (CD14+CD16+) (Figure 1).