CD4 and ventilator-associated pneumonia: Among the decreased subsets in VAP vs. HC, the CD4+ hybrid Th1-Th17 cells (CD45RO+CD45RA ̄CXCR3+CCR6+), co-expressing CXCR3/CD183 and CCR6/CD19646, unexpectedly remained low at each time point (Figs. 2b and 3g, h).