TTF1 and neoplasm: Acinar ADC LF20 maintained the CK7+/CK20−/TTF-1+ staining pattern throughout all passages (Figure 4B, Supplementary Figure S5K), while acinar ADC sample LF19 preserved the original expression of the primary tumor until passage X1 but lost CK7 and TTF-1 expression in passage X2 (Supplementary Figure S5I), and sample LF01 lost CK7 expression (Supplementary Figure S5A).