Likewise, possible ubiquitin-mediated degradation of SST5 remains to be elucidated, although recent results showed a relationship between the abundance and functionality of ubiquitin-specific peptidase 8 and the degree of SST5 expression at both mRNA and protein levels, which could bear clinical relevance for treating corticotroph adenomas (Hayashi et al., 2016). Here, SSTR5 is linked to ACTH-producing pituitary gland adenoma.