Artificial 4-hydroxytamoxifen-inducible intein sequence. Insertion of the intein into a protein of interest blocks the function of the tagged protein. 4-hydroxytamoxifen is used to induce intein self-splicing (excision of the intein from the protein sequence and ligation of the flanking sequences), thus restoring the function of the tagged protein in a small molecule-dependent manner (PMID:15247421).