Fig 1: SPINK4 and ITLN1 mark early goblet cells. a Volcano plot showing fold change and P value of genes differentially expressed in the ‘goblet-type’ cell cluster as compared to all other cell clusters (see Fig. 3). Points coloured red indicate genes significant at 5% permutation test. Selected highly significant genes are labelled. b Bar chart showing the percentage of cells in the ‘goblet-type’ cell cluster (n = 98) expressing MUC2, ITLN1 or SPINK4 alone or in different combinations (thresholds set at the tenth centile to include 90% of cells in which at least one transcript was detected from each gene). c Triple immunofluorescence staining images of MUC2 (red), ITLN1 (white) and SPINK4 (green) in normal colon from a resection specimen (blue stain is DAPI). Scale bar, 100 µm. d Triple immunofluorescence staining images of MUC2 (red), ITLN1 (white) and SPINK4 (green) in normal oesophageal epithelium obtained by endoscopic biopsy (blue stain is DAPI). OSGs encroaching on the surface epithelium are shown in the enlarged images on the right. Scale bars are 200 µm and 50 µm in enlarged images. e Triple immunofluorescence staining images of KRT14 (white), KRT7 (green) and MUC2 (red) in an OSG beneath normal squamous epithelium from an endoscopic biopsy of normal squamous epithelium from a patient with BO biopsy (blue stain is DAPI). Scale bar 50 µm. f Representative immunofluorescence staining of Barrett’s EMR specimen containing intestinal metaplasia but no dysplasia for MUC2 (red), ITLN1 (white) and SPINK4 (green); nuclei (DAPI) in blue. Scale bars are 400 µm and 100 µm in enlarged images