TOP1 and skin cancer: TP53 mutations (e.g., p.Arg213*, p.Arg249Trp, and p.Arg248Gln) are frequently observed and are associated with a more aggressive clinical course. Other genetic alterations include TACC3-FGFR3 and ROS1-GOPC fusions, NF1-truncating mutations, NRAS mutations, TOP1 amplification, and PTEN deletions. These findings suggest that the molecular pathogenesis of TC may overlap with that of other skin cancers, providing potential targets for therapy [16].