Arney is a strong advocate for involvement of women in science, technology, engineering, and mathematics (STEM), but "hates pink" - she considers attempts to make science look more "girlie" to be patronising and unnecessary.[16]
From 2004 to 2016 she was science communications manager for Cancer Research UK.[17] One notable success in this role was the "#NoMakeupSelfie" hashtag as it trended in August 2014; this was noted by CRUK's social media team who used a photograph of Arney – one of the charity's main media spokespeople – to publicise the SMS number for donations. After more than 5 million views, the hashtag raised in excess of £8 million for Cancer Research UK.[18]
Her first book, Herding Hemingway’s Cats, which was published in January 2016 by Bloomsbury Publishing, covers the state of knowledge of the human genome, the advances made since the 1950s and what remains unknown. It also addresses misconceptions about epigenetics and non-DNA inheritance.[19][20]
In 2020 she published the book Rebel Cell: Cancer, Evolution, and the New Science of Life's Oldest Betrayal.[21]
Her sister Helen Arney is a musician with whom she sometimes collaborates.[22]
^K. L. Arney; S. Erhardt; R. A. Drewell; M. A. Surani (2001). "Epigenetic reprogramming of the genome—from the germ line to the embryo and back again". The International Journal of Developmental Biology. 45 (3): 533–540. PMID11417896.