MUC1 and bronchopulmonary dysplasia: Wang et al. reported levels no higher than 200 U/ml, whereas Ogihara et al. reported that KL-6 plasma levels of 199 U/ml at week 1 or 232 U/ml at week 2 are excellent predictors of moderate/severe BPD in patients <28 weeks GA (positive predictive values of 83% and 80%, respectively) [13, 16].