What I could see from the (paywalled) article is a graph with data points to which a linear regression was applied. I sur hope that the article explains why su

What I could see from the (paywalled) article is a graph with data points to which a linear regression was applied. I sur hope that the article explains why such fit and that there is a biological theory for a linear relationship between the variables. Fitting everything linearly is an early sign of misunderstanding of statistics and quality of the conclusions.