TNFRSF1A and neoplasm: Although recent reports have established that tumor growth was impaired in TNF KO and TNFR1 KO but not TNFR2 KO, those mice were injected with B16K1 melanoma cells, a genetically-modified cell line obtained from B16F10 cells, which stably express the MHC-I (major histocompatibility complex) molecule H-2Kb [15].