Wohlfarth P, et al. - Authors here reported torquetenovirus (TTV) plasma dynamics and investigated clinical associations in patients following allogeneic hematopoietic stem cell transplantation (HSCT). They recognized a universal occurrence of TTV viremia and this remained sustained throughout the first year after HSCT. TTV levels appeared to have an association with several variables and events prior to and after HSCT, this suggested immune-marker properties of TTV. However, in this population, their complex interactions could perturb the capability of TTV to predict immune-related complications.