PLPP2 and idiopathic pulmonary fibrosis: Specifically, the high expression of CERS6 (OR: 2.110, 95%CI: 1.361–3.273, p = 8.534 × 10−4) and SPHK1 (OR: 1.177, 95%CI: 1.002–1.384, p = 4.781 × 10−2) was positively correlated with an increased risk of IPF, while the elevated levels of PLPP2 (OR: 0.707, 95%CI: 0.530–0.943, p = 1.849 × 10−2), KDSR (OR: 0.803, 95%CI: 0.681–0.947, p = 9.274 × 10−3), and CERS2 (OR: 0.726, 95%CI: 0.538–0.980, p = 3.621 × 10−2) were negatively associated with IPF risk (Figure 2A and Supplementary Table S3).