The teaching and learning of immunology has always been a difficult objective, but the experts in the field believe it can be an interesting area of study if people are taught in a manner that will give them a maximum understanding. One way of going round this problem is presenting lectures and other learning resources in a digested/watered down form. This way, people with limited science background could easily learn and understand the subject. This book is a compilation of lecture notes that span across four important topics in immunology namely: acute promyelocytic leukaemia, apoptosis, phagocytosis and systemic lupus erythematosis. In this book, every effort has been made to present the text in a lucid and readable style without sacrificing the important details. This book will therefore be of great interest and utility for students, researchers, teachers and doctors of medical and other allied sciences who want basic understanding of immunology. It is here to remove the fearof students for whom immunology has become a no go area.