On the other hand, gene expression is associated with tumor and disease development, including MMP13 (matrix metallopeptidase 13), SERPINB4 (serine protease inhibitor serpin family B member 4), SOCS3 (suppressor of cytokine signaling 3) and SLC26A4 (Solute Carrier Family 26 Member 4), which were up-regulated after the infection with either the WT Salmonella or mutant strain, as shown in panel C. Finally, keratinocyte-fibroblast co-cultures are another promising 3D model for studying skin infections caused by various pathogens, including Staphylococcus aureus MRSA bacteria [133]. Here, MMP13 is linked to skin infection.