The upregulated activity of glutaminase (GLS) in cancercells promotesde novo synthesis of GSH by facilitating the production of essentialraw material (glutamate) of GSH.120 However,the excessive accumulation of GSH in cancer cells attenuates the PDT-elicitedtumor immunogenicity by scavenging PDT-generated 1O2. The gene discussed is GLS; the disease is cancer.