It was proposed that HIF-1a expression, induced by hypoxia in the TME, inhibited IL-18-mediated NF-κB activation in tumor-infiltrating NK cells, contributing to their defective function and uncontrolled tumor progression in the RMA/S lymphoma model that exhibit impaired expression of Major Histocompatibility Complex (MHC)-I [99]. This evidence concerns the gene HIF1A and neoplasm.