Immunogen sequence: QQHTLPVTLS PALSQELLKT VPPPVNTHQE QMKQPTPLPP PCQKVPVELP VEVPSKQEEK HMTAVKGLPE QECEQ. Involucrin, a component of the keratinocyte crosslinked envelope, is found in the cytoplasm and crosslinked to membrane proteins by transglutaminase.