The CD14 marker is dimly expressed in which type of cells?

CD14 is a surface marker that is predominantly expressed on monocytes and macrophages. In the context of flow cytometry and immunophenotyping, monocytes typically exhibit a dim expression of CD14 compared to other myeloid cells. This characteristic expression level is significant because it distinguishes monocytes from other leukocyte types, such as T cells, B cells, and natural killer (NK) cells, which do not express CD14 or do so at very minimal levels.

Monocytes can be further classified into classical (CD14++CD16−), intermediate (CD14++CD16+), and non-classical (CD14+CD16++) subsets, but all typically show a dim expression pattern for CD14 on the flow cytometry profile when comparing to the bright expression seen on activated macrophages. The CD14 marker is a co-receptor for toll-like receptors (TLRs) and is crucial in immune response, making the identification of monocytes through CD14 expression important in both research and clinical settings.

In contrast, T cells, B cells, and natural killer cells express different sets of surface markers that are used for their identification. T cells express CD3, B cells express CD19, and NK cells express CD56, none of