UCMP, Umeå University, Umeå, Sweden. per.stenberg@molbiol.umu.se|UCMP, Umeå University, Umeå, Sweden. per.stenberg@molbiol.umu.se|UCMP, Umeå University, Umeå, Sweden. per.stenberg@molbiol.umu.se|UCMP, Umeå University, Umeå, Sweden. per.stenberg@molbiol.umu.se|UCMP, Umeå University, Umeå, Sweden. per.stenberg@molbiol.umu.se