Histopathology confirmed the exophytic mass to be a low-grade spindle-cell type gastrointestinal stromal tumour (GIST) (Fig. 3A) with positive staining for KIT proto-oncogene markers CD117 and DOG1, whilst liver biopsies showed non-necrotising epithelioid granulomas consistent with sarcoidosis (Fig. 3B). This evidence concerns the gene KIT and sarcoidosis.