IGFBP2 and amyotrophic lateral sclerosis: In fact, a viscous circle is set in motion whereby negative feedback on GH production (and hence ALS production) and possible inhibitory effects of big IGF‐II on 150 kD complex formation causes increasing amounts of especially big IGF‐II and mature IGF‐II to end up in binary complexes with mainly IGFBP‐2, IGFBP‐4, and IGFBP‐6, and/or remain in the free form.