| We observed significant changes in the abundance of several proteins , which fall into three general classes : ( 1 ) TCDD independent and exclusively strain specific ( e . g . isoforms of the protein disulfide isomerase A 3 , regucalcin , and agmatine ureohydrolase ) ; ( 2 ) strain independent and only dependent on TCDD exposure ( e . g . aldehyde dehydrogenase 3A1 and rat selenium binding protein 2 ) ; ( 3 ) dependent on both TCDD exposure and strain ( e . g . oxidative stress related proteins , apoptosis inducing factor , and MAWD binding protein ) . ^^^ |