Lacrimal gland function. (A) Epidermal growth factor (EGF) concentration measured in tear washings from different strains. NT, not tested. (B through D) Spearman correlations between tear EGF concentrations and muscarinic 3-receptor band densities (B, measured in Western blot; P = 0.001), lacrimal gland (LG) CD8+ T (C, P = 0.002), and CD4+ T cells (D, P = 0.004). Percentage of CD8 and CD4 infiltration was measured with flow cytometry. R2, coefficient of determination.