Table 2 Caucasian seroconverters were analyzed for MACS, MHCS, and SFCC cohorts and the combination of all cohorts. The alleles *B*35* and *Cw*04* are each considered as codominant allele variables in a Cox proportional hazards model, that is, the allele variable has a value of 0, 1, or 2 corresponding to the number of copies of the allele carried by the individual. The analysis for *B*35/+* and *B*35/B*35* considers the effect of*B*35* without taking into account the presence or absence of*Cw*04; *likewise, the analysis of *Cw*04* ignores the effect of *B*35*. Because these two alleles are in strong, positive linkage disequilibrium in Caucasians (24) (that is, on most chromosomes where one of these alleles is present the other is present also), an additional analysis was made for individuals carrying one of these alleles but not both. The three pairs of columns on the right give the results of analyses in which heterozygosity for *B*35*but not *Cw*04*, for *Cw*04* but not *B*35*, and for *B*35* and *Cw*04* together were considered as explanatory variables in a Cox model. Homozygotes for either or both of these alleles were excluded from this analysis (39). The results of a survival analysis in which the RH was adjusted by considering the protective genotypes of *CCR5*,*CCR2*, and *SDF1* (15) as additional covariants were virtually identical to the unadjusted RH and*P* values presented here (27). Failure to observe significant association for either *HLA-B*35 *or*HLA-Cw*04* for MHCS and SFCC may reflect small sample size or a biased depletion of very rapid progressors to AIDS in both of these cohorts (20, 32), diminishing ability to observe *HLA B*35* and *Cw*04* influence on rapid progression. Dashes indicate no data available.