For example, the BCL9 gene polymorphisms are thought to be associated with negative symptoms in schizophrenia, as mentioned gene product is involved in the Wnt signalling pathway, a conserved pathway regulating crucial processes of cell fate determination in metazoan animals, including humans, which is significant in neuroplasticity, neurogenesis and cell survival [46, 100–103]. Here, BCL9 is linked to schizophrenia.