CCR9 and COVID-19: The roles of CCR1, CCR2, CCR3, CCR5, CCR9, XCR1, and CXCR6 in COVID-19 severity have already been described [4,[11], [12], [13]], whereas limited or no information is available regarding CCRL2. The CCRL2 gene codes for C-C chemokine receptor-like 2, a class-A G protein-coupled receptors (GPCRs) structurally related to the atypical chemokine receptor (ACKR) family, a small subclass of CKRs.