We have previously reported that the E2 open reading frame of human papillomavirus type 6b (HPV6b) was expressed in Bombyx mori cell line Bm-N as a fusion protein with baculovirus polyhedrin. Here we show that antibody against this E2-polyhedrin fusion protein recognized a putative gene product as a 49-kDa protein in some genital condyloma and laryngeal papilloma tissues, which were associated with HPV6 and HPV11, by immunoblotting analysis. The antibody reacted also with antigens in the nucleus of cells in the middle and upper layers of these papilloma tissues.