Professor of Infectious Disease and Microbiology & Immunology at University of California, San Francisco; member of the UCSF Comprehensive Cancer Center; her laboratory researches the complex interplay of microbial pathogens with eukaryotic cells; she was a speaker at a panel discussion held at the University of California, San Francisco on May 1, 2002, addressing career issues faced by LGBT scientists within the scientific community.

Joanne Engel's and her lover Ellen Haller's son, Danny once remarked on the roles of his own nine grandparents, since Ellen and Joanne co-parent with two gay men, and one of the grandparent couples had split up and re-married. They also commented on trying to control the amount of gifts and relationships since there were so many grandparents (hard to do).