All participants:  All participants must be ≥18 years of age.  Due to distorting effects on immune parameters and immune responses, participation is either not possible or must be delayed in case of the following:  active hepatitis B/C or signs of acute infections active or recent malignant condition (i.e. <12 months ago treated) active systemic auto-immune or auto-inflammatory conditions (such as rheumatoid arthritis, inflammatory bowel disease). use of immunosuppressive medication pregnant  HIV elite controllers:  HIV elite controllers in the 2000HIV that have an available first-degree relative. Definition of HIV elite controller is the same as in the 2000HIV, see definition on page 7 of the protocol and in the group description.  ART-suppressed people living with HIV:  As a control group, ART-suppressed people living with HIV in the 2000HIV that have an available first-degree relative will be included.  ART-suppressed people living with HIV need to apply to the following criteria to participate in the 2000HIV: ≥18 years, on cART ≥6 months with an HIV-RNA load <200 copies/mL.  For this 2000HIV-trained study, additional criteria for ART-suppressed people living with HIV are:  Never applied to controller definition. At least one documented HIV RNA load >100.000 copies/mL No documentation of recent HIV acquisition combined with ART initiation in less than 6 months.  Eligible ART-suppressed people living with HIV will be matched by sex and age (max. 5-10 years apart), where possible. Similarity in family members between groups will also be pursued. That is why the HIV elite controllers and their family members will be enrolled first. Thereafter, the ART suppressed people living with HIV and their family members will be recruited and enrolled.  First-degree relatives:  Aside from the criteria for all participants mentioned above, there are no additional criteria for first-degree relatives of participants with HIV. If multiple first-degree relatives are available, siblings are preferred. If no sibling is available, then children >18 years. If no children >18 years, then parents. If there is still multiple options, same-sex will be preferred over different-sex relatives.