In one specific example from the literature, the off-to-on switching of cell-surface structures such as pyelonephritis-associated pili [52] in many enteric bacteria is environmentally regulated by a number of factors including the CpxAR two-component regulatory system, the Histone-like nucleoid structuring protein H-NS (a non-specific NAP) and cAMP-catabolite gene activator protein [53]. This evidence concerns the gene CTNNBL1 and pyelonephritis.