CEACAM5 and colon adenocarcinoma: [250] similarly studied thiol‐specific PEGylation of bispecific antibody fragments targeting the carcinoembryonic antigen (CEA) and CD3 for human colon adenocarcinoma (PEG‐S‐Fab) and reported increased half‐life, plasma stability, and in vivo cytotoxic effect in mice.