MICB and Merkel cell skin cancer: Somewhat unexpectedly, MICA mRNA was expressed only at very low levels in the MCC tumors and cell lines when compared to genes commonly expressed in MCCs such as RB1, E2F2, ENO2 or RPLP0. The MICB mRNA expression level was also low compared to those genes, but generally higher than for MICA. On the GSE22396 Array a subset of tumors (24%) were characterized by moderate to high levels of MICB mRNA.