CD8A and melanoma: When compared to IL2, the differentiating characteristics of NKTR-214 include: 1) receptor bias towards the heterodimeric IL2Rβγ found on CD8 and NK cells leading to markedly higher CD8 to Treg ratios (> 400) in the tumors of murine melanoma; 2) improved single-agent efficacy and synergistic efficacy when combined with checkpoint blockade; 3) improved tolerability with no hypotension or vascular leak syndrome in cynomolgus monkeys at the maximum tolerated dose (MTD); and 4) a PK profile that allows antibody-like dosing regimens [16].