Affinity maturation of IgG synthesized by tetC^HIGH, tetC^INT, and tetC^NEG PCs. A total of 86 different IGVH3 gene sequences were obtained from isolated PC subsets of 4 different individuals, and the numbers of R and S mutations present in the CDR1 and CDR2, as well as the corresponding R/R + S ratio, were calculated. The theoretical R/R + S ratio value calculated for random mutations⁴⁵  is shown as a dotted line. Results represent the mean plus or minus SEM of the different sequences obtained (n = 33, 32, and 16 for isolated tetC^HIGH, tetC^INT, and tetC^NEG PCs, respectively). *Statistically significant differences.