GRPR and gastrointestinal stromal tumor: However, the expression of the GRPR in GIST has not been extensively studied.<h4>Materials and methods</h4>GRPR expression was evaluated using immunohistochemistry in two separate tissue microarrays from patients treated at Sahlgrenska University Hospital, one from the pre-TKI era (1983-2001) and the other from the post-TKI era (2014-2020).