It has been previously demonstrated through tissue microarrays stained for either tyrosine-phosphorylated STAT3 or tyrosine-phosphorylated STAT5 that activation of these STATs was mainly a property of the tumor cells, and not the surrounding tissue, and that STAT staining was largely seen in the nuclei of tumor cells, most likely indicating canonical STAT function [35]. The gene discussed is STAT5A; the disease is neoplasm.