Chromosomal instability and a deregulated cell cycle are intrinsic features of high‐risk gastrointestinal stromal tumours with a metastatic potential oleh Heidi Maria Namløs, Ksenia Khelik, Sigve Nakken, Daniel Vodák, Eivind Hovig, Ola Myklebost, Kjetil Boye, Leonardo A. Meza‐Zepeda