It was shown that the TNF-family members [TNF-α and lymphotoxin-alpha (LT-α)] play a key role in chronic/progressive anemia development by signaling via their dedicated receptors [TNF-R1 or p55 (CD120a), TNF-R2, or p75 (CD120b)] (see Table 1) (118). The gene discussed is TNF; the disease is anemia (phenotype).