Interestingly, 74-year-old Varmus, currently director of the US National cancer Institute, had done his apprenticeship in a mission hospital in Bareilly in 1960s.
He received 1989 Nobel Prize in Physiology or Medicine for his discovery of the cellular origin of retroviral oncogenes.
During his 30-minute interaction with Modi, which lasted for about half an hour, the two discussed a wide range of public health care issues, including those related to cancer research, vaccine and possibilities of research in India.
"The Prime Minister invited him to visit India on a regular basis. The professor congratulated Modi on the laws in India on anti-smoking," the spokesperson Ministry of External Affairs told reporters.
Recollecting his India days in 1960s, Varmus also talked about how medicines have evolved since them.