CD40 and colorectal carcinoma: As tumor cell fusion partner, the MSI+ CRC cell line HCT116 was chosen because the mutational status of many coding microsatellites (cMS) is well known (Table 1), it shares human leukocyte antigen (HLA)-A02 as restriction element with the CD40 Bs of the healthy donor and it has been shown to be accessible to lysis by cytotoxic T lymphocytes (CTL) [8,10].