Leo Schalkwyk has been actively publishing research in the field of genomics since 1986. In that time he has worked on species including Archaea, yeast, pufferfish, chicken, cow, pig, mouse and man. The focus has always been on developing methods and resources for finding the function of genes and systems, which he considers the central challenge of biology. Several of his earliest methodology papers are still being cited today. At the Institute of Psychiatry he has been working on behavioural genetics in mouse and human, and on integrating gene-function information in human and mouse.