John held adjunct appointments at George Washington and Georgetown Universities and contributed to a number of book chapters with Norman Salzman, Peter Howley, Yosef Aloni, P. Hollsberg, D. Hafler, K. Khalili, Irvin Chen, and Rafi Ahmed. He served on the editorial boards of the Journal of Virology and AIDS Research and Human Retroviruses, as well as a number of other journals. John chaired many meetings, including the Cold Spring Harbor RNA Tumor Virus Meeting and the HTLV-1 Retrovirus International Conference and organized the meeting on posttranslation modification of p53 held at the NCI. He published more than 202 papers in peer-reviewed, high-impact journals, including, but not limited to, Journal of Virology, Nature, Journal of Experimental Medicine, PNAS, and Molecular Cell.