It is relevant to observe, however, that mean SPVL for non-VB (the ‘control’ group) is 0.22 log10 copies/ml higher than the viral loads from the UK backbone phylotype (4.79 versus 4.57) —probably due to the inclusion of samples from well-documented early infections in the former—and CD4 model coefficients of VB and the UK VOIs detected here are only 11–25 cells/mm3/year apart. The gene discussed is CD4; the disease is infection.