Respondents whose most recent CD4 cell counts were ≥200 cells/μL may have been started on PCP prophylaxis based on a declining trend in CD4 cell counts, may not have had CD4 cell counts that were ≥200 cells/μL for at least 3 months, or may not have accurately recalled their most recent CD4 count. This evidence concerns the gene CD4 and pneumocystosis.