Expression quantitative trait loci data from mammary tissue (n = 396) in the Genotype Tissue Expression database (version 8; https://gtexportal.org/home/ accessed on 9 October 2019) and tumour tissue (n = 799) in The Cancer Genome Atlas eQTL browser (https://albertlab.shinyapps.io/tcga_eqtl/ accessed on 9 October 2019) provided no evidence that CCVs are associated with DUSP4 expression in normal or tumour breast tissue. The gene discussed is DUSP4; the disease is neoplasm.