Figure 1.

Altered CLL-NK ligand–receptor interactions. Ligand–receptor pairs are color-coded by their activating (green) versus inhibitory (red) effects on NK cells. Changes are listed as increases (↑), decreases (↓), or no change (–) and are similarly color-coded according to whether the measured change is expected to increase or decrease NK activation, as well as the relevant citations listed. Different studies have found varying (and, at times, conflicting) changes in ligand and receptor expression levels that broadly point to decreased NK activity against CLL. NKG2DL refers to the ligands of NKG2D (MICA, MICB, ULBP1-6).