EXOSC4 and infection: To evaluate if known miRNA-degrading enzymes are involved in the turnover of miR-29b-2-5p during Shigella infection, we tested whether the knockdown of RRP41 (ribosomal RNA-processing protein 41; core component of the exosome complex), PNPT1 (polyribonucleotide nucleotidyltransferase 1, aka PNPaseold-35) and XRN1 [28], could affect the regulation of miR-29b-2-5p in the context of infection.