PRF1 and chronic obstructive pulmonary disease: This is a groundbreaking study in there has never been a study prior to their publication that addressed “cardiovascular relaxation and recovery of homeostasis in CAD patients.” Jia et al. [44] found a decrease of perforin and granzyme B expressions accompanied by decreased levels of pro-inflammatory cytokines and stress hormones in 20 patients diagnosed with COPD indicating some of the potential health benefits of SY for individuals living with COPD.