The relative abundance of sipA, sipC, hilA, and rng mRNA gradually increased as hns mRNA levels decreased during infection (Fig 3C); therefore, we hypothesized that increased RNase G levels downregulate hns transcript expression in S. Typhimurium infecting host cells or under anaerobic conditions, thus enhancing SPI-1 T3SS gene expression. Here, SPI1 is linked to infection.