The four likely TD genes span a range of biological pathways and functional ontologies and are all clearly brain expressed (Kang et al., 2011; Kapushesky et al., 2012; Petryszak et al., 2014, 2016). Indeed, these genes provide interesting avenues for additional investigations: WWC1, also known as KIBRA (kidney and brain expressed protein), is a cytoplasmic phosphoprotein that shows evidence of interaction with multiple proteins and pathways (Kremerskothen et al., 2003; Rebhan et al., 1997; Zhang et al., 2014). For instance, it may be a transcriptional co-activator of estrogen receptor 1 (ESR1), regulate the collagen-stimulated activation of ERK-MAPK cascade, and regulate the Hippo/SWH signaling pathway (Zhang et al., 2014). It has been demonstrated to have roles in cell polarity, migration, and trafficking, as well as learning and memory (Schneider et al., 2010). It is also likely regulated by PRKCZ (protein kinase C zeta), a kinase known to play a role in synaptic plasticity and memory formation (Büther et al., 2004).
