7. Any medical condition (such as but not limited to severe/unstable angina, history of myocardial infarction, coronary/peripheral artery bypass graft, symptomatic congestive cardiac failure, cerebrovascular accident or transient ischemic attack, pulmonary embolism) or laboratory abnormality(ies) which might make it difficult for the subject to participate in the study, at the discretion of the Principal Investigator (PI)or co-PI