Pathologists may be more likely to examine CD30 expression on all cells in a biopsy sample, including malignant cells and cells in the tumor microenvironment, and report both, as proposed by an expert panel of hematopathologists in a recent publication of best practices for CD30 IHC assessment.39 Lastly, laboratories may be validating CD30 IHC assays to detect lower levels of CD30 expression for therapeutic purposes versus diagnostic only. Here, TNFRSF8 is linked to neoplasm.