CLDN6 and osteosarcoma: CLDN6 membranous staining was absent in MRTs (five samples from four different patients), osteosarcoma (50 samples from 12 patients), rhabdomyosarcoma (64 samples from 21 different patients), neuroblastoma (110 samples from 24 different patients) and in two mesoblastic nephroma samples from two patients (Figure 5 and Supplementary Table S1).