Glioma is the largest group of intrinsic brain tumours that can lead to life loss of 20 years as a result of late diagnosis and poor outcomes coming after it. Diagnosis and assessment of glioma currently rely on a combination of imaging techniques, histology and molecular profiling. If there could be a blood-based liquid biopsy adopting a minimally invasive way, diagnosis and recurrence monitoring would be easier and more affordable. Previous studies suggested the linkage between the biomarker of glial fibrillary acidic protein (GFAP) and disease prognosis; serum GFAP levels are associated with prognostic markers and progression-free survival. However, early stages of brain tumour growth usually go undetected, leading to a lack of in vivo data that brings hardship to the development of technique or tool for the purposes. A group of British scientists have developed an in silico model (computer simulation of pharmacologic or physiologic process) to understand current limitations, uses and strategies for blood-based biomarkers for brain tumours. The findings were indicative, such as the adoption of multiple GFAP detection cut-off limits for different tumour severities. To build a more complex and realistic model, better understanding of the processes which govern biomarker transport through brain tumours and into the bloodstream is still needed.