Figure 2 Serum levels of mannan‐binding lectin (MBL) in the families stratified into five families with and four families without low MBL genotypes compared with 330 adult Icelander controls. Whereas members of the five families with low MBL have MBL levels overall similar to that of the controls (p = 0.2), members of the four families without low MBL genotypes have significantly higher MBL levels (p<0.001) and the distribution is, as expected, similar to that for the high MBL genotype (fig 1). Box plots show the median values and interquartiles, and the bars show the 10th centiles of MBL concentrations.