XCL1 and COVID-19: In contrast, genes related to nuclear factor kappa B (NF-kB) downstream chemotactic and inflammatory responses, such as nuclear factor kappa B subunit 1 (NFKB), C-C motif chemokine ligand 20 (CCL20), C-X-C motif chemokine ligand 1 (CXCL1), CXCL6, CXCL2, CXCL3, and CXCL5, presented significantly higher expressions in amnion than chorion during COVID-19-affected pregnancies (Fig. 2J).