Investigating Genetic Polymorphisms of Factors Related to Apoptotic Clearance, Milk Fat Globule Epidermal Growth Factor-8 (MFG-E8) and Phosphatidylserine Receptor (PSR), in Rheumatoid Arthritis and Systemic Lupus Erythrematosus=類風濕性關節炎及全身紅斑性狼瘡與凋亡細胞清除相關因子---乳脂肪小球表皮生長因子 8 (MFG-E8)及絲胺酸磷脂接受器(PSR)之基因變異性分析