Substance-P analogues including [D-Arg1,D-Phe5,D-Trp7,9,Leu11]-substance-P (SP-D) and [Arg6,D-Trp7,9,NmePhe8]-substance-P (6–11) (SP-G) inhibit the growth of SCLC cells by modulating neuropeptide signalling. Here, TAC1 is linked to small cell lung carcinoma.