Based on the data reported to date, the aim of this study was to further investigate the putative in vivo correlation between the expression of β‐arrestins 1 and 2 with sst2, sst5 or dopamine receptor type 2 (D2) and also the association between β‐arrestins expression with the response to first‐generation SRL and with the presence of cavernous sinus invasion in somatotropinomas. This evidence concerns the gene SSTR5 and growth hormone-producing pituitary gland neoplasm.