For instance, atypical T cells in CTCL lesions stain positive for the highly angiogenic protein VEGF-A, and malignant CTCL cell lines produce VEGF-A via a JAK- and c-Jun N-terminal kinase (JNK)-dependent mechanism in vitro (Krejsgaard et al., 2006; Miyagaki et al., 2017; Sakamoto et al., 2018). This evidence concerns the gene MAPK8 and primary cutaneous T-cell non-Hodgkin lymphoma.