CD8A and asthma: Thus, in order to clarify this issue of human NK-like (CD8+CD28−) T cells having or not “regulatory” properties in human asthma, further studies are needed, involving a thorough phenotypic and functional characterization of both peripheral blood and bronchial CD8+CD28−CD57+ as well as CD8+CD28−CD57− T cells in patients with bronchial asthma of different degrees of severity as well as in non-asthmatic controls.