Tissera Names Sir Roy York Calne, Reputed Surgeon and Transplantation Expert, to Scientific Advisory Board.

Business Editors/Health/Medical Writers

TEL AVIV, Israel--(BUSINESS WIRE)--April 22, 2004

Tissera, Inc. (OTCBB:TSSR), a biotechnology company dedicated to the development and commercialization of tissue transplantation therapies utilizing novel tissue precursor regeneration technologies for the treatment of disease and organ transplantation, has appointed Roy York Calne, M.D., to the company's Scientific Advisory Board. Sir Roy Calne, who was granted the Knight Bachelor Honors in 1986, is a revered professor, author and surgeon in the field of transplantation surgery.

Currently Emeritus Professor of Surgery at the University of Cambridge and Professor of Surgery at the National University of Singapore, Dr. Calne is also a general surgeon and consultant in transplantation surgery. Among his many prestigious appointments, Dr. Calne served as Senior Vice-President of the Royal College of Surgeons of England. Since the publication of his first book, Renal Transplantation, in 1963, Dr. Calne has published over 18 books, hundreds of articles and lectured at some of the world's most admired medical schools including Harvard University, University of Cambridge, University of London, and Oxford University.

"It is an honor to have one of the great minds in transplantation medicine join our Scientific Advisory Board," said Vicki Rabenou, CEO of Tissera. "Dr. Calne has been a pioneer in the field since 1959, when he engaged in organ transplantation research and described the first effective immunosuppressive treatment for kidney transplantation. He started the Cambridge Kidney Transplant Program in 1965, and the first European Liver Transplant Program in the late 60's. He brings more than 40 years of insight, research and hands-on experience to our Board."

Dr. Calne is also acclaimed for being the first surgeon to perform a pancreas transplant in the United Kingdom in 1979 and the first to perform an intestinal transplant in the country in 1992. Former President of the International Transplantation Society, Dr. Calne has been awarded numerous distinctions and honorary degrees countries and prestigious academic institutions around the world for his groundbreaking work in medicine.

About Tissera

Tissera is a biotechnology company dedicated to the development of novel tissue precursor regeneration technologies for treating gene deficiencies and diseases in which organ transplantation is necessary, while minimizing the dosage of immunosuppressive drugs. Tissera licensed the worldwide exclusive rights to the technology developed at the renowned Weizmann Institute of Science in Israel led by Professor Yair Reisner, who currently serves as the Chief of Tissera's Scientific Advisory Board. In this research, scientists successfully implanted embryonic human and porcine kidney precursor tissues in mice, which grew into functional kidneys. This research was published in Nature Medicine and attracted worldwide scientific and media attention. For more information, please visit: www.tissera.com.

Safe Harbor Statement

"Statements in this document that are not purely historical are forward-looking statements. Forward-looking statements in this release include statements regarding our developing technology into a useful product, our moving forward with our plans for trials, and our plans to expand the Company's infrastructure. Actual outcomes and our actual results could differ materially from those in such forward-looking statements. Factors that could cause actual results to differ materially include risks and uncertainties such as the inability to further finance our plans and unforeseen technical difficulties in developing our technology, which could among other things, delay or prevent product development and our planned results. For further risk factors see the Company's 10-KSB filed with the SEC for our latest fiscal year."