High expression of S100A8/A9, along with RETN, ALOX5AP and reduced expression of MHC class II HLA-DR genes has recently been used to define immunosuppressive MS1 monocytes in sepsis38 and proportional increases in these immune-suppressive monocytes has been detected in both sepsis and COVID-1939, however these immunosuppressive monocytes have not been identified in other acute infections such as dengue40. Here, RETN is linked to Sepsis.