Mullis wrote that he began to question the AIDS consensus while writing a NIH grant progress report and being unable to find a peer-reviewed reference that HIV was the cause of AIDS. He published an alternative theory of AIDS in 1994, and questioned the scientific validity of the link between HIV and AIDS, leading some to label him an "AIDS denialist." Mullis has been criticized for his association with HIV skeptic Peter Duesberg, claiming that AIDS is an arbitrary diagnosis used when HIV antibodies are found in a patient's blood. In 2006, Mullis wrote the foreword to the book "What If Everything You Thought You Knew About AIDS Was Wrong?" by Christine Maggiore, an HIV-positive AIDS denialist whose 3-year-old daughter died of AIDS-related pneumonia in 2005, and herself died of an AIDS-related illness in 2008. According to journalist Coby McDonald, Mullis' HIV skepticism influenced Thabo Mbeki's denialist policymaking throughout his tenure as president of South Africa from 1999 to 2008, contributing to as many as 330,000 unnecessary deaths. An article in the "Skeptical Inquirer" described Mullis as an "AIDS denialist with scientific credentials has never done any scientific research on HIV or AIDS." However, he consulted for Specialty Labs, in Santa Monica, developing a nucleic acid based HIV test. Seth Kalichman, AIDS researcher and author of "Denying AIDS", "[admits that it seems odd to include a Nobel laureate among the who's who of AIDS pseudoscientists". In 2010, Mullis gave a talk at Google at which he was asked about his controversial views on AIDS and HIV. Mullis said "I'm come to the conclusion... that the thing that causes AIDS is not a species of the retroviridae, it's the whole genus. The people who get sick have a whole lot of different versions...that's my feeling."