In concordance with our observations in the Tothill data set comparing both tumour sites, the peritoneal cancer cell line S129 showed lowest expression of these genes, B4GALNT3 and B4GALNT4, compared to the nonovarian and ovarian cancer cell lines (n = 7), therefore reflecting the absence of LacdiNAc‐type N‐glycan structures in this primary PC cell line (S129). The gene discussed is B4GALNT3; the disease is pachyonychia congenita.