STAT3 gain of function (EFO_0010647, an Experimental Factor Ontology entry) can be described as follows. STAT3 GOF is a rare genetic disorder of the immune system. Signal transducer and activator of transcription 3 (STAT3) is a transcription factor which is encoded by the STAT3 gene in humans. Germline gain-of-function (GOF) mutations in the gene STAT3 causes this early-onset autoimmune disease characterized by lymphadenopathy, autoimmune cytopenias, multiorgan autoimmunity, infections, eczema, and short stature. Also known as: STAT3 GOF.