Interestingly, alongside a strong pro-inflammatory cytokine response, we observed an elevated expression of IFN-β as well as type I IFN-stimulated genes (ISGs), such as Interferon-induced GTP-binding protein Mx1 (MX1) and Interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) in C. acnes infected THP-1 cells in the delayed phase of infection. This evidence concerns the gene IFNB1 and infection.