Fibroblast growth factor 5 (FGF-5) has effects of inhibiting hair growth and shifting hair growth cycle from the growth stage to the regression stage in hair matrix cells.

However, two-stage estimates of regression coefficients corresponding to these two estimates have approximate equal mean square error.

In the stage I, called as data preprocessing, the support vector machines for regression (SVMR) approach is used to filter out the outliers in the training data set.