A test of tumour tissue from a patient with metastatic colorectal cancer (stage IV), requested by a specialist or consultant physician, to determine if: (a) requirements relating to rat sarcoma oncogene (RAS) gene variant status for access to cetuximab or panitumumab under the Pharmaceutical Benefits Scheme are fulfilled, if: the test is conducted for all clinically relevant mutations on KRAS exons 2, 3 and 4 and NRAS exons 2, 3, and 4; or a clinically-relevant RAS variant is detected; and, in cases where no RAS variant is detected (b) the requirements relating to BRAF V600 gene variant status for access to encorafenib under the Pharmaceutical Benefits Scheme are fulfilled.