ICOSLG and systemic lupus erythematosus: We hypothesize that this apparently contradictory result is due to the effect of other inhibitory receptors; thus, in healthy individuals the inhibitory receptors ILT2 and ILT4 could play a secondary role in the generation of tolerance of DC, while other molecules, like PDL-1, OX-40L, and ICOSL, may play a crucial role in inducing that regulatory phenotype; conversely, in SLE patients, the existence of a function impairment of the receptors mentioned above may highlight the inhibitory effect of ILT2 and ILT4 not observed in healthy controls.