CLOCK and cancer: In 399 of the 409 microdissections, mutations could be entirely attributed to the clock-like signatures SBS1, SBS5, and SBS40; these are mutational signatures that are ubiquitous and increase linearly with age across normal tissues and cancers (Alexandrov et al., 2015, 2020; Blokzijl et al., 2016; Lee-Six et al., 2019; Moore et al., 2020; Yokoyama et al., 2019; Yoshida et al., 2020).