NR0B2 and Guillain-Barre syndrome: In addition, in chemically defined medium, at least three genes are under the control of this mechanism: shp and gbs1556 (encoding a secreted protein), which are positively and directly controlled by SHP/RovS, and the fbsA gene, which codes for a fibrinogen-binding protein involved in GBS pathogenesis (Schubert et al., 2004) and is repressed by SHP/RovS.