ALDH1L1 and inverted urothelial papilloma: To further characterize the distinct pathobiology of IUP, we identified DEPs (permutation-based t-test FDR <0.05) between IUP and PUC, namely, PKP2, PYGB, SERPINH1, and TUBB, and those between IUP and NU, namely, ALDH1L1, JUP, COL14A1, and VIM (Figure 2A and Supplementary Figures S3A, B).