The overexpression of CAMK2N1 had been reduced in the progression of medullary thyroid cancer,16 colon cancers17 and PCa.15, 18 In the current report, we found the low expression level of CAMK2N1 in both DR PCa patient tissues and PC‐3‐DR cells, which was consistent with previous studies.15, 18 Moreover, our finding indicated that in DR PCa cells, ectopic expression of CAMK2N1 largely reduced its proliferation, survival and growth while remarkably enhanced its docetaxel‐induced apoptosis. This evidence concerns the gene CAMK2N1 and medullary thyroid gland carcinoma.