The invention relates to a double-stranded compound, preferably an oligoribonucleotide (siRNA), which down-regulates the expression of a human TGaseII gene at the post-transcriptional level. The invention also relates to a pharmaceutical composition comprising the compound, or a vector capable of expressing the oligoribonucleotide compound, and a pharmaceutically acceptable carrier. The present invention also contemplates a method of treating a patient suffering from a fibrotic disease such as pulmonary, kidney and liver fibrosis or ocular, scarring comprising administering to the patient the pharmaceutical composition in a therapeutically effective dose so as to thereby treat the patient. The invention also relates to treatment of fibrotic and other diseases by use of antibodies to TGaseII polypeptide.