Blanco E, et al. - Researchers studied the age-related distribution of memory B-cell (MBCs) and plasma cell (PCs) expressing different immunoglobulin heavy chain (IgH)-isotypes, in addition to the immature/transitional and naive B-cell compartments. They noted that early in life, PCs reached maximum values, followed by MBCs and plasma IgH-isotypes. Importantly, different patterns were demonstrated by IgH-isotypes from different IGHC (immunoglobulin heavy chain constant region) gene-blocks, probably reflecting consecutive cycles of IgH-isotype-switch recombination through life.