Potent and specific cellular inhibitor of CaM-kinase II (CAMK2) (PubMed:11444830). Traps Ca(2+)/calmodulin on CAMK2 (By similarity). {ECO:0000250|UniProtKB:Q9Z2N6, ECO:0000269|PubMed:11444830}. This is the function of Ensembl gene identifier ENSG00000163888 (CAMK2N2, calcium/calmodulin dependent protein kinase II inhibitor 2).