PTPRC and cancer: Fig 4B and 4C, show that CCT2 was detected in spiked MDA-MB-231 and T47D-CCT2 cells with minimal background inference in the column five. Rows 4, 5, 9, and 10 show typical spiked cancer cells that were CK positive and CCT2 positive. Rows 6 and 7 show examples of spiked cancer cells that were CK dim, as indicated by the red arrows, but were CCT2 positive and CD45 negative. These non-leukocytic cells would have been missed by the classical definition for CTC. Images in Fig 4 also showed that spiked cancer cells have variations in CCT2 staining intensity.