Regulates phosphorylation of a number of proteins involved in translation regulation including EIF2A, EIF4EBP1 and RPS6KB1. May be involved in the endoplasmic reticulum stress response (By similarity). Expressed in various types of thyroid tumor such as papillary thyroid carcinomas and oxyphilic thyroid tumors but not in normal thyroid tissue (at protein level). Strongly expressed in heart, skeletal muscle, pancreas, white blood cells and prostate with moderate expression in colon and spleen. Expressed in renal carcinoma cells but not in normal kidney. 'Niban' means 'second' in Japanese. Belongs to the Niban family. Truncated N-terminus.