The repression of de novo NAD(P) synthesis genes nadA, nadB and nadC (BCG1632, BCG1633, BCG1634; Rv1594, Rv1595, Rv1596) and the absence of significant changes in expression of pncA, pncB, nadD and nadE (BCG2062c, BCG1392c, BCG2437c, BCG2457c; Rv2043c, Rv1330c, Rv2421c, Rv2438c) involved in NAD(P) synthesis and salvage [39] (Data set S1), indicates that bacterial NAD(P) may become limited during infection. Here, BEX3 is linked to infection.