Lastly, the excellent negative predictive value of some biomarkers does allow exclusion of a diagnosis, avoiding undue treatment toxicity and extra costs [132]. Tailoring therapy to biomarkers Of the vast array of inflammatory markers, procalcitonin has been most extensively investigated [130]. Specificity and sensitivity are too low to guide initiation of antibiotics in cancer patients with suspected sepsis, leaving this decision to be taken on clinical grounds [129, 133]. Procalcitonin might possibly be used to guide duration of antibiotic therapy in critically ill cancer patients with sepsis [129]. Regarding AKI, in addition to creatinine, tubular injury markers such as NGAL or cell cycle arrest markers (TIMP-2, IGFBP7) [134,135,136] have been evaluated to detect renal injury or stress. While these biomarkers might provide additional insight into the pathophysiology of AKI and have predictive value, they are currently not used in daily clinical practice [137]. Although several strategies to prevent further renal damage in patients with (or at risk of) AKI are available [138], determination of a biomarker does not have therapeutic consequences at the moment. Studies are needed to describe the kinetics and predictive value of markers of both inflammation and renal injury in this specific group. Last, research should address the safety of antibiotic-sparing measures (de-escalation, shorter courses, biomarker-guided decision trees) in cancer patients with and without neutropenia and whether these are effective for limiting emergence of resistance. Impact of critical illness on long-term outcomes We suggest including variables such as disease-free and event-free survival, as well as quality-adjusted life-years (QALYs) in studies on critically ill cancer patients. Also, assessment, treatment, and prevention of post intensive care syndrome in this population is important. Moreover, acute brain dysfunction is highly prevalent in mechanically ventilated patients with cancer [139], and long-term cognitive impairments occur in patients that develop delirium in the ICU [140]. An increased number of patients are discharged alive from hospital. However, advances in community palliative care and the increasing number of hospices have made it possible for patients to be discharged from hospital to die at home or in a hospice. Studies to better identify a patient’s trajectory following ICU discharge are warranted. Similarly, additional studies are warranted to show that critical care management serves as a bridge to optimal therapy and cure. Such data will encourage clinicians to use alternative strategies of ICU admission (mostly time-limited trials). Studies to demonstrate that earlier recognition of cancer patients at risk of life-threatening deterioration and potential benefits from rapid response teams are needed. Moreover, more data are needed to guide clinicians on a daily basis during time-limited trials. Finally, in cancer patients, who at best are discharged to the wards to receive curative treatment, studies are warranted to assess the impact of early rehabilitation and transition programs on ICU-acquired weakness, functional status, sarcopenia, and other physical outcomes that are affected by both critical illness and the malignancy. Understanding/managing toxicity of targeted therapy, immunotherapy, and biotherapy Optimal dosing of targeted therapy and biotherapy is not well established and they have a narrow therapeutic margin. Pulmonary toxicity is rare but life-threatening and includes bronchospasm,