Described herein are human transgenic beta cells expressing fugetactic levels of CXCL12 to a subject in need thereof. Also described herein are beta cells comprising a transgene comprising a nucleic acid sequence encoding CXCL12.本發明描述向有需要之個體表現趨除量之CXCL12的人類轉殖基因β細胞。本發明亦描述包含含有編碼CXCL12之核酸序列的轉殖基因的β細胞。