Sharad Kumar has made seminal contributions to two areas of fundamental biology: the understanding of programmed cell death, and the regulation of protein homoeostasis. He discovered one of the first mammalian caspases; a novel family of ubiquitin ligases; and a ubiquitin-like protein (Nedd8) involved in a novel protein-modification system now termed Neddylation. His group discovered and characterised a large part of the Drosophila cell death machinery and defined a novel cell death program during development. His discoveries have contributed fundamental knowledge to the fields of cell death, caspases, animal development, cancer biology and ubiquitination.