Natural killer (NK) cells lead immune surveillance against cancer and early elimination of small tumors. Owing to their ability to engage tumor targets without the need of specific antigen, the therapeutic potential of NK cells has been extensively explored in hematological malignancies. In solid tumors, however, their role in the clinical arena remains poorly exploited despite a broad accumulation of preclinical data. In this article, we review our current knowledge of NK cells’ biology, and highlight the challenges facing NK cell antitumor strategies in solid tumors. We further summarize the abundant preclinical attempts at overcoming these challenges, present past and ongoing clinical trial data and finally discuss the potential impact of novel insights on the development of NK cell-based therapies.

Anemia in cancer patients is associated with poor quality of life, reduced response to therapy, and decreased overall survival. We describe a case of a 56-year old woman with advanced metastatic non-small cell lung carcinoma who demonstrated marked response to a novel combinational immunotherapy approach involving a long-acting PEGylated construct of recombinant human Interleukin-10 with Nivolumab, an anti-PD-L1 checkpoint inhibitor. While on treatment, the patient developed severe anemia and hyper-ferritinemia requiring RBC transfusion support. Here we discuss a possible novel immune mechanism of IL10-mediated anemia in correlation with tumor response.