Extinction _____. only happens above the species level cannot happen to more than one species at a time has happened to over 99% of species that ever lived on earth happens when a species or population dies out.
Medical use. Nivolumab is used as a first line treatment for inoperable or metastatic melanoma in combination with ipilimumab if the cancer does not have a mutation in BRAF, and as a second-line treatment for inoperable or metastatic melanoma following treatment of ipilimumab and, if the cancer has a BRAF mutation, a BRAF inhibitor.
Nivolumab binds PD-1 with high affinity (KD 2.6 nmol/l by Scatchard analysis to polyclonally activated human T cells) and blocks its interactions with both B7-H1 and B7-DC. It effectively inhibits the interaction between PD-1 and its ligands.