PCSK1N and cancer: We designed this regimen hypothesising that the administration of SAAs between two subsequent administration cycles of chemotherapy could sensitise tumour cells with neuroendocrine differentiation to the apoptotic effect of many different cytotoxic drugs, including CDDP and etoposide, and could contribute to delaying the recovery of drug-resistant or less sensitive cancer cells that usually occurs in the long (21–28 days) inter-cycle resting period.