Researchers aren't clear what the precise role of HHV-8 may be, though it appears that it may cause malfunctioning immune system cells to reproduce rapidly.

CNN: Castleman disease

Generally, people with unicentric Castleman disease aren't infected with HHV-8.

CNN: Castleman disease

Infection by a virus called the human herpesvirus 8 (HHV-8) is associated with Castleman disease, and doctors suspect that it may play a role, especially in multicentric Castleman disease.

CNN: Castleman disease

Among the allegations: Chapin, who retired from Winchester, Calif-based HHV several years ago, siphoned off money to other pet charitable causes that amounted to self-dealing, paid himself too much in compensation, and countenanced improper accounting maneuvers that made HHV seem far more financially efficient than it really was.

FORBES: California Sues 'Nonprofit Entrepreneur' Roger Chapin And Charity Forbes Exposed

The lawsuit also questions a Virginia condominium that HHV bought in 2006 and various gold-club memberships.

FORBES: California Sues 'Nonprofit Entrepreneur' Roger Chapin And Charity Forbes Exposed

The lawsuit says that HHV improperly classified much of its direct-mail fundraising costs as charitable-purpose expenditures, which makes the charity look more noble.

FORBES: California Sues 'Nonprofit Entrepreneur' Roger Chapin And Charity Forbes Exposed

The sum was so large that HHV one year made the Forbes largest-charities list, while the Coalition was able to claim extremely high financial efficiencies.

FORBES: Charity Regulators (Finally) Eye Overvaluation Of Donated Goods