The study by Kenny et al. is of considerable importance. They concluded that there was a weak association between the ergothioneine levels and maternal age, and if a threshold was set at the 90th percentile of the reference range in the control population (≥462 ng/ml), only one of these 97 women (1%) developed preeclampsia, versus 96/397 (24.2%) whose ergothioneine level was below this threshold. These results suggest that there might be a dichotomized association between ergothioneine concentrations and preeclampsia; and only a high ergothioneine level over 90th percentile of the control population could be protective against preeclampsia. With the kind supply of the dataset from the authors, further analysis using univariable as well as multivariable analyses were performed while allowing for non-linearity between ergothioneine concentrations and risk of preeclampsia using a 3-knot restricted cubic spline function. The univariable results showed that ergothioneine had a significant non-linear association with preeclampsia and it would start to offer protective effect from 300 ng/ml onward. The results were similar to the multivariable analysis. In addition, the analysis also confirmed that body mass index was significantly associated with an increased risk of preeclampsia.