<prompt> Zollinger Ellison syndrome is caused by -Gastrin secreting tumorSomatostatin secreting tumorCCK secreting tumorAdrenalin secreting tumor  <response>: Ans. is a i.e., Gastrin secreting tumor o Zollinger-Ellison syndrome is caused by gastrin-secreting tumors.o These gastrinomas are most commonly found in the small intestine or pancreas. 