NSP1 and NSP2 have been shown to dimerize and to bind a promoter region called the infection box in the MtEnod11 promoter, but also to activate the expression of ERN1, another TF involved in both rhizobial infection and nodule organogenesis (Andriankaja et al., 2007; Middleton et al., 2007; Cerri et al., 2012). This evidence concerns the gene ERN1 and infection.