Figure 1.

The publication history of chromosomes 21 and 22. (a) The number of articles in PubMed [8] that include 'chromosome 21' or 'chromosome 22' and 'human' in their title or abstract. (b) Chromosome publications weighted by sequence length. The number of publications since June 2000 has been multiplied by a factor of 10 to make the trend more visible. (c) Chromosome publications weighted by gene content per chromosome. The number of publications since June 2000 has been multiplied by a factor of 10 to make the trend more visible.