Question special

Looking for your opinion on the appropriate use of β-D-glucan and galactomannan assays for the diagnosis of invasive aspergillosis. I am often asked to interpret two common scenarios: an appropriate host (e.g. Allo-HSCT) with appropriate imaging but negative serum fungal markers, and a less appropriate host (e.g. solid malignancy such as lung cancer), questionable imaging and positive fungal markers. Where do you find these tests to be helpful in clinical practice?