As human beings with trillions of cells, each of which has their associated millions of copies of myriad proteins and other biological molecules, it’s something of a miracle that enough of the molecules bump together at the right times to keep us alive and functional. In addition to our own cells, we also coexist with microscopic neighbors, including various beneficial bacteria, while fending off pathogens like disease-causing bacteria, viruses, protozoans, and fungi. We often consider the bacteria and viruses in most human diseases, which invoke our immune systems to fight them to keep us healthy, but it also makes sense that the fungi can affect us as well, a topic in cancer research that is gaining attention.

With a background in both immunology and cancer biology, I’ve always had a fascination with the interplay between the body’s immune system and any tumors that might pop up. Originally, it made sense that the immune system would actively seek out and destroy cancerous cells, but the emerging consensus is that the interactions between cancers and host immunity is far more complex. In addition to growing new blood vessels and reprogramming metabolic processes, there appears to be some imbalance between avoiding immune cells while also promoting tumor-infiltrating inflammatory cells to promote its growth. ¹ (Figure 1) Trying to dissect this apparent contradictory relationship between tumors and host immunity remains a hot topic.