S100A9 and carcinoma: Furthermore, it was reported that S100A8 and S100A9 were detected by using two-dimensional gel electrophoresis showing that there was the increased expression of these two proteins in CRC tissues [10], and that elevated expression of S100A8 and S100A9 was associated with poor differentiation in carcinomas of breast, lung, and thyroid gland [7]–[9].