This paper considers nonparametric estimation in a varying coefficient model with repeated measurements (Yij, X tj , t u), for i = l,...,n and j = l,...,n h where X u = (X iJ0 ,..., X ijk) r and (Yy, X tJ , t tJ) denote the yth outcome, covariate and time design points, respectively, of the ith subject. The model considered here is Y u = XjjPitij) + £i(t u), where fi{t) = {fi o (t),..., j? t (t)) T , for k ^ 0, are smooth nonpara

These data suggest that hyperinsulinemia is an independent risk factor for breast cancer and may have a substantial role in explaining the obesity-breast cancer relationship.