FOLR1 and cancer: In fact, the only published data relevant to this topic reports the binding of an antibody with reactivity towards both FR-α and FR-β in ovary and lung carcinomas [34] and the FR-α and FR-β mRNA levels in ovarian and fallopian adenocarcinomas [11], which often correlate poorly with protein expression [35, 36], leaving considerable uncertainty over the relative FR protein levels in these cancers.