CD4 and tuberculosis: Tier-2 is an extended POCT tier; a small co-operative ‘POC-hub’, or mini-laboratory, servicing up to 8-10 referring clinics (within a 10-20km radius) where CD4 and/or tuberculosis testing can be implemented into an existing community laboratory that already provides baseline general pathology services, including basic haematology, chemistry (alanine transferase) and sexually transmitted disease (STD) testing required for ART initiation [17].