Notably, in Liang et al., several genes encoding NAD+ synthesis enzymes (e.g., NNMT, NAMPT, KYNU, and NQO1) were downregulated in IPF AEC2s, and the impact of this exciting observation on regulating the Zn/ZIP8/SIRT1 axis and on solving the puzzle of fibrosis remains to be elucidated. Here, NNMT is linked to idiopathic pulmonary fibrosis.