VSIR and obstructive sleep apnea syndrome: In this line, the expression of VISTA did not correlate with OSA severity parameters (data not shown), while the percentage of monocytes that expressed high levels of SIGLEC-5 (SIGLEC-5hi,determined as shown in Supplementary Figure 5A) positively correlated to AHI and ODI parameters, indicating that SIGLEC-5 increases along OSA severity (Figures 5B, C).