When he was four years old, his father Bjarne Lie lost his job as a lawyer due to problems with the Nazi authorities.
Intrigued by the recent discovery of the double helix, and by how it raised new questions of life and death, he asked to be Jøssum's assistant at Kaptein Wilhelmsens og Frues bakteriologiske institutt.
In 1961, he received a scholarship to go to Rochester to study molecular genetics on microbes, and continued his research upon his return to Oslo.
While working in the paediatric department in Rikshospitalet, he immediately fell in love with a six-year younger medical student named Kari Helene Elise Kveim upon meeting her in the hospital canteen in April 1967.
They married on 7 December that same year, and spent their honeymoon in a Palestine refugee camp in Jordan, after Israelis had seized the Westbank during the June war in 1967 and left many Palestinians homeless.
But the new drugs were potentially going to offer real hope of cure for cancer and leukaemia which only a few years before had been almost invariably fatal.
That was the starting point for the Nordic Society for Pediatric Hematology and Oncology (NOPHO), formally established in 1984, where Lie would be a driving force.
Lie convinced the Director General of WHO, Gro Harlem Brundtland (whom he knew from medical school) to give a grant of $100,000 to get PODC started.
This has been hugely successful and India and the surrounding countries now have networks of care providing excellent treatment for children with cancer.
In South Africa he initiated a collaboration with Peter Hesseling, to develop a cost effective treatment for Burkitt's lymphoma, which at the time had a terrible prognosis.