An antigen is a tiny piece of a substance — often a protein on a virus, a bacterium, or another cell — that the body reads as not me. When the immune system notices it, it can make antibodies, which are tools shaped to fit that antigen. So the antigen is the trigger; the antibody is the reply.

An antigen「antigen」（抗原） is是 a tiny piece of a substance某種物質的一小部分 often a protein通常是蛋白質 on a virus, a bacterium, or another cell在病毒、細菌或其他細胞表面的 that the body reads as not me被身體判讀為「不是我自己的東西」 When the immune system notices it當免疫系統注意到它時 it can make antibodies就會製造出抗體（antibodies） which are tools shaped to fit that antigen也就是被塑造來對付那個抗原的工具 So the antigen is the trigger所以抗原是觸發者 the antibody is the reply抗體是回應

You meet antigens all the time: on germs, on pollen, on some foods. Blood types are antigen differences on red blood cells (A and B are names for antigens). A vaccine puts in antigens, or a safe copy of them, so your body can practise making antibodies without you having the full illness.

You meet antigens all the time你會不斷遇到抗原 on germs在病菌上 on pollen在花粉上 on some foods在某些食物上 Blood types are antigen differences血型就是抗原的差異 on red blood cells在紅血球表面 (A and B are names for antigens)（A 型和 B 型就是抗原的名稱） A vaccine puts in antigens疫苗會放入抗原 or a safe copy of them或是抗原的安全複製品 so your body can practise making antibodies好讓你的身體練習製造抗體 without you having the full illness卻不用真的得那場病

Though actually not every antigen is an enemy. Your own cells have antigens too; the body is supposed to leave those alone, and trouble starts when it does not, as in some autoimmune illness.

Though actually不過實際上 not every antigen is an enemy不是每個抗原都是敵人 Your own cells have antigens too你自己的細胞也有抗原 the body is supposed to leave those alone身體本應該對這些抗原置之不理 and trouble starts when it does not一旦沒有做到，麻煩就開始了 as in some autoimmune illness就像某些自體免疫疾病那樣

The word looks as if it contained gene, as in DNA; say it AN-ti-jen. The -gen piece is an older scientific bit meaning that which produces, taken in from French.

The word這個字 looks as if it contained gene看起來好像包含了 gene as in DNA就像 DNA 裡的那個 gene say it AN-ti-jen但它的發音是 AN-ti-jen The -gen piece-gen 這個部分 is an older scientific bit是個較古老的科學詞根 meaning that which produces意思是「產生出…的東西」 taken in from French是從法文借來的