Classical vs Non-classical Monocytes

Cited from Monocyte Wiki

There are at least three types of monocytes in human blood:

1. The classical monocyte is characterized by high level expression of the CD14 cell surface receptor (CD14++ CD16− monocyte)
2. The non-classical monocyte shows low level expression of CD14 and additional co-expression of the CD16 receptor (CD14+CD16++ monocyte).
3. The intermediate monocyte with high level expression of CD14 and low level expression of CD16 (CD14++CD16+ monocytes).