Indeed, in limited prior screening of acute SCLS sera, we found elevated levels of pro‐inflammatory mediators including TNFα, CXCL10, CCL2 and IL‐8.2, 3 To more fully probe the SCLS proteome, we performed SOMAscan profiling of 1305 proteins in nine matched plasma samples obtained by venipuncture during acute or convalescent intervals. Here, CCL2 is linked to Systemic capillary leak syndrome.