Fig 2: Verification of GPNMB, ERAP2, CTSC, and NPC2 in individual FNA cystic fluid samples by Western blot analysis(A) Equal amounts of proteins (20 µg) prepared from individual FNA cystic fluid samples were separated by 6-18%-gradient SDS-PAGE, transferred to PVDF membranes, and probed with specific antibodies against the indicated target proteins. SFTPB, which was previously reported as a potential PTC biomarker, was also included in this analysis. (B) The Coomassie-Blue-stained protein profile was used as a loading control.

Fig 3: Establishment of human alveolospheres(A) Schematics of sorting-based isolation and establishment of alveolospheres from human lung tissues.(B) Representative bright-field images of an alveolosphere (left) and airway organoid (right).(C) Immunostaining of HT2-280 (green, left), SFTPC (green, middle), and AQP5 (green, right) in alveolospheres.(D) Representative gating strategy for sorting HT2-280+ EPCAM+ human AT2 cells.(E) Transmission electron microscopy images of alveolospheres. Microvilli (MVs) were observed in spheres at the apical lumen. The inset (right) shows a lamellar body (LB).(F) An MA plot comparing the transcriptomes between alveolospheres (n = 4) and airway organoids (n = 2) (passages 4–6). Genes with false discovery rate (FDR) < 0.01 are shown in dark gray. Representative genes that are upregulated in alveolospheres (green) and airway organoids (blue) are highlighted. Dotted lines show log2 (fold change) values of 1 and -1.(G) Co-staining of SFTPB (green) and AQP5 (red) in alveolospheres. Nuclear counterstaining, Hoechst 33342 (C and G). Scale bar: 2 µm (E, right), 10 µm (E, left), 25 µm (B, right, C, and G), and 100 µm (B, left).See also Figure S1.