(A) Insulin-like growth factor I receptor (IGF-I-R), (B) insulin receptor (IR), and (C) hybrid IR/IGF-I receptor (Hybrid-R) content (mean ±SEM) of normal thyroid (n = 7) and cancer thyroid specimens. PTC, papillary thyroid cancer (n = 8); FTC, follicular (poorly differentiated) thyroid cancer (n = 6); ATC, anaplastic thyroid cancer (n = 4).