However, when NK cells were activated in a variant of RPMI-based feeder medium wherein FBS was replaced with human AB serum (RPMI-hAB), we observed, alongside a consistent percentage of TIM-3+ NK cells (Figure 4E), a significant decrease in TIM-3 MFI levels of 1816 Intensity Units on human NK cells after exposure to cancer cells (Figure 4F). The gene discussed is HAVCR2; the disease is cancer.