Dear Mark, i miss you so much already it makes my heart ache!  I cannot believe you have gone!  I miss our chats, our giggles, our “putting the world to rights”, the mischief oh and of course – the science!  I don’t think i have ever met anyone else so passionate about their work.  I loved your mindset, you were a great mentor and I enjoyed every moment that we spent together at the microscope with you teaching me how to drive it.  You bring science to life with your funny little drawings explaining “how it was”.  Thank you for being such an amazing line manager, mentor and dear friend.  I hope in some small way your legacy will live on through my own work.  At peace now, but never forgotten and always in my heart.  love Sheena x