Leszek Krzysztof Borysiewicz[REF]) was born in Cardiff, Wales, United Kingdom, to Jan and Zofia (née Wołoszyn) Borysiewicz, ethnic Polish World War II-era refugees (from what is present-day Belarus) who came to Great Britain with the Anders' Army [REF].
Borysiewicz studied medicine at Cardiff University School of Medicine and received a PhD from the Imperial College London in 1986 for his thesis, entitled Cell mediated immunity to human cytomegalovirus infection (cytotoxic T cell and natural killer cell mediated lysis of human cytomegalovirus infected cells) [REF].