NTRK1 and breast neoplasm: To determine the extent to which JAK2–STAT3 and TrkA signaling pathways are co-activated in breast tumor samples, we performed IHC staining on 33 node-positive breast carcinomas across three major subtypes (triple-negative, HER2-enriched, and luminal subtypes) to detect phosphorylated TrkA (Y490) and STAT3 (Y705) proteins.