However, other studies have qualified this hypothesis by showing that the majority of macrophages infiltrating temporal arteries of GCA patients resemble non-classical monocytes with CD16 and CX3CR1 expression, but often lack CCR2 expression [111,112], suggesting that both classical and non-classical monocytes are involved in GCA and that further studies focusing on monocytes and macrophages are needed. This evidence concerns the gene CX3CR1 and temporal arteritis.