To model the impact of stromal SULF2 on tumour cell growth, we used COS-7 cells (African green monkey kidney embryonic fibroblasts expressing high endogenous SULF2, with 98.5% homology to human SULF2; https://www.ensembl.org BLAST [16]), alongside manipulating SULF2 expression in human liver LX-2 myofibroblast cells, which have low levels of endogenous SULF2 (Fig. 2a, b). The gene discussed is SULF2; the disease is neoplasm.