However, these computational deconvolution methods are reference-based in that they explain bulk profiles as linear combinations of a priori defined profiles of constituent cell types that have previously been physically isolated, thus precluding data-driven discovery of recurrent states of cancer cells and their comparison to established tumor classification (e.g., Luminal, Basal, and HER2 breast cancer subtypes). The gene discussed is ERBB2; the disease is neoplasm.