HSPD1 and pulmonary arterial hypertension: Specific pattern of expressed WT PAH comprised of 29.9% ± 11.3% of oligomers, 58.7% ± 15.2% of catalytically active tetramers and 11.4% ± 9% of dimers and co-cultivation with GroEL/ES bacterial chaperones resulted in insignificant increase in tetramers up to 60.5% ± 2.9%, followed with 34.8% ± 3.5% of oligomers and 4.6% ± 3.7% of dimers.