The analysis of the transcriptional profile of all the genes encoding MDR EPs revealed that the genes emrK and mdfA (MFS family), mdtJ (SMR family), acrE and cusB (RND family), and mdtK (MATE family) are invariably induced during the infection of both U937 and Caco-2 cells, although at different extent (Figure 2). Here, LYPD4 is linked to infection.