In response to double-strand DNA breaks, TP53INP1 promotes p53/TP53 phosphorylation on 'Ser-46' and subsequent apoptosis. TP53INP1s and HIPK2 could be partners in regulating p53 activity. TP531NP1 plays a significant role in the progression of anaplastic carcinoma or contributes to anaplastic transformation from papillary or follicular carcinoma.