FOLR1 and breast cancer: Fortunately, ApoStream technology and laser-scanning cytometry using antibodies against FRα have enabled the detection of FRα-positive circulating tumor cells (CTCs) in blood samples across different cancer types, such as NSCLC (n = 14), breast cancer (n = 20), and ovarian cancer (n = 6), which can be compared to samples from healthy subjects (n = 20) [60].