A note of caution for using calmodulin antibodies

Calmodulin (CaM) is a ubiquitous intracellular calcium receptor that regulates a plethora of cellular functions through interactions with target proteins. In mammals, an identical Calmodulin protein is expressed by 3 independent genes (CALM1, CALM2, CALM3). Therefore, antibodies generated against either of the three products (CaM1, CaM2, CaM3) of these genes cannot be distinguished, and conclusions based on the supposedly specific CaM antibodies claiming functions of one of the 3 genes may be misleading. In this paper we present 44 articles, using such antibodies for Western blot, ELISA assay, immunohistochemistry or which are based on proteomics and the use of databases with incorrect annotations, all potentially reaching misleading conclusions. This should be taken as a note of caution for researchers working with Calmodulin antibodies and misleading databases. •The three independent Calmodulin genes in mammals encode an identical protein.•Antibodies supposed to specifically detect Calmodulin 1,2 or 3 recognize Calmodulin derived from all three Calmodulin genes. We reviewed misleading conclusions based on the use of Calmodulin antibodies and wrong proteomic annotations in 44 articles.