In vitro, MPXV infection of human cells does not induce interferon-stimulated gene (ISG) expression and further suppresses Tumour Necrosis Factor alpha (TNF-α), Interleukin 1 alpha and beta (IL-1α and β), C-C Motif Chemokine Ligand 5 (CCL5) and Interleukin 6 (IL-6) activation in primary fibroblasts [48]. Here, CCL5 is linked to infection.