Among them are the CgNIN, encoding a transcriptional factor, expressed at pre-infection stages in root hairs competent for Frankia infection (Clavijo et al., 2015) and Cg12, encoding a subtilase, whose expression is linked to the infection of root hairs and cortical cells by Frankia (Laplaze et al., 2000; Svistoonoff et al., 2003). Here, PCSK5 is linked to infection.