MUC1 and cancer: One group exploited the Qβ phage display system to rapidly and efficiently generate a library of 20 peptides of mucin‐1 (MUC1), a glycoprotein expressed on cancer cells.100 MUC1 is expressed by many types of cancer cells and is therefore an interesting target for cancer immunotherapies.101, 102 By incubating phages expressing the various epitopes with sera from immunized mice, a region of interest (SAPDTRPAP) was discovered.