Duba wurin da ke ƙasa sannan ka amsa tambayar daga baya a cikin harshe ɗaya kamar yadda wurin yake:  Hanyar wucewa: Wani muhimmin aiki na tsarin garkuwar jiki shi ne gano da kuma kawar da ciwon daji. Wannan ake kira tsaro na rigakafi. Kwayoyin ciwon daji da suka canza suna bayyana antigens da ba a samu a cikin ƙwayoyin halitta na al'ada. Ga tsarin garkuwar jiki, waɗannan antigen suna kama da baƙi, kuma kasancewarsu yana sa ƙwayoyin garkuwar jiki su kai wa ƙwayoyin ciwon daji da suka canja hari. Antigens da ciwon sukari ke nunawa suna da tushe da yawa; wasu sun samo asali ne daga ƙwayoyin cuta na oncogenic kamar ƙwayoyin papilloma na mutum, wanda ke haifar da cutar sankarar mahaifa, yayin da wasu sun kasance sunadarai na kwayoyin da ke faruwa a ƙananan matakan a cikin ƙwayoyin halitta amma sun kai manyan matakan a cikin ƙwayoyin ciwon daji. Misali daya shine enzyme da ake kira tyrosinase wanda, idan aka bayyana shi a manyan matakan, ya canza wasu ƙwayoyin fata (misali melanocytes) zuwa ciwon daji da ake kira melanomas. Tushen na uku na antigens na ciwon daji sune sunadarai masu mahimmanci don daidaita haɓakar kwayar halitta da rayuwa, wanda yawanci ke canzawa zuwa kwayoyin da ke haifar da cutar kansa da ake kira oncogenes. Babban amsar tsarin rigakafi ga ciwon daji shine lalata ƙwayoyin cuta marasa amfani ta amfani da ƙwayoyin T masu kashewa, wani lokacin tare da taimakon ƙwayoyin T masu taimako. An gabatar da antigens na ƙwayar cuta a kan kwayoyin MHC na aji na I a cikin irin wannan hanyar zuwa antigens na kwayar cutar. Wannan yana ba da damar ƙwayoyin T masu kashewa su gane ƙwayoyin ƙwayar cuta ba daidai ba ne. Hakanan ƙwayoyin NK suna kashe ƙwayoyin ƙwayar cuta ta irin wannan hanyar, musamman idan ƙwayoyin ƙwayar cuta suna da ƙananan ƙwayoyin MHC na aji na I a farfajiyar su fiye da yadda aka saba; wannan lamari ne na yau da kullun tare da ciwon daji. Wani lokaci ana samar da kwayoyin cutar kan ƙwayoyin ƙwayar cuta wanda ke ba da damar lalata su ta hanyar tsarin haɗin gwiwa. A bayyane yake, wasu ƙwayoyin cuta suna guje wa tsarin rigakafi kuma suna ci gaba da zama ciwon daji. Kwayoyin ƙwayar cuta sau da yawa suna da ƙarancin adadin kwayoyin MHC aji na I a farfajiyar su, don haka gujewa ganowa ta hanyar kwayoyin T masu kashewa. Wasu ƙwayoyin ƙwayar cuta kuma suna sakin samfurori waɗanda ke hana amsawar rigakafi; misali ta hanyar ɓoye cytokine TGF-β, wanda ke hana ayyukan macrophages da lymphocytes. Bugu da kari, rigakafin rigakafi na iya bunkasa kan kwayoyin cutar, don haka tsarin garkuwar jiki ba zai sake...  Tambaya: Menene ciwon daji ke nunawa?
ƙwayoyin cuta