TIGIT and HIV infectious disease: We found that Siglec-9+ CD56dim NK cells, during HIV infection, exhibit higher expression of several NK activating/cytotoxic receptors and markers including CD16 (% and mean fluorescence intensity (MFI)), CD38 (% and MFI), NKp30 (% and MFI), DNAM-1 (% and MFI), and perforin (%); and lower expression of the inhibitory receptor NKG2A (MFI) and TIGIT (% and MFI), compared to Siglec-9- CD56dim NK cells (Fig 2B and 2C).