Importantly, all the acromegaly-associated Subtype 1 tumors (co-expressing POU1F1 and NR5A1) formed a distinct cluster located closer to the PIT-1 group than to SF-1 tumors, reflecting their much higher similarity to PIT-1-positive than gonadotroph PitNETs. The gene discussed is POU1F1; the disease is acromegaly.