Fig. 1. TGFβ type II-B receptor is an alternatively spliced form of TβRII. (A) The amino acid sequence of TβRII-B compared with TβRII contains an insert of 26 amino acids after Ser31, replacing Val32 of TβRII. The insertion sequence of human TβRII-B is underlined. A potential N-linked glycosylation site (Asn48) and two Cys residues (Cys44, Cys47) are shown in shaded boxes. (B) Schematic outline of alternative splicing of the tβrII-intron 1 resulting in an additional exon, exon 1A.