My fellow Cambridge-London commuters; did you work it out? Once you know that it depicts a gene, it’s annoyingly obvious. But despite travelling past it by train about three days per week, I failed to identify the thousands of brightly coloured bars painted on the cycle path next to the rail track near Cambridge’s Addenbrooke’s hospital as a nucleotide sequence. It should have been a clue that only four colours are used.

It probably comes from generally not being very biochemistry minded, as a straight-physics editor. Nevertheless, a friend of mine mentioned he had heard about the biology-inspired cycle path artwork and after some quick Googling, the rumour was confirmed; the colourful sequence stands for the BRCA2 gene, implicated in breast cancer and discovered in 1995.

What a good idea to combine scientific topics with railway scenery. After five years of commuting I would welcome more of these puzzles along the rail track to keep me entertained!

Liesbeth

Liesbeth Venema (Senior Editor, Nature)