These include: What are the requirements of supporting evidence? How large is definitely a clinically relevant effect? What degree of specificity and level of sensitivity are required? Does a given marker influence decision making and have medical utility? In many cases, the answers to these questions remain unfamiliar, and ultimately, the query of whether PGT is definitely valid and useful must be identified empirically – Development and Validation of DDP-4 inhibitors and prognosis of COVID‐19