This novel anti-CEACAM5 maytansinoid conjugate comprises three key components: (i) a humanised monoclonal antibody specifically targeting CEACAM5-expressing epithelial tumours, (ii) a cleavable sulfo-SPDB linker designed for tumour-selective payload release, and (iii) the potent cytotoxic agent DM4 (a maytansine derivative) [83]. The gene discussed is CEACAM5; the disease is neoplasm.