And, because this tumor’s unusual expression profile nearly matched that of a rare normal PNEC (#50, Figure 6B and C), which like the tumor cells expressed NPW, NMB, CARTPT, KCNK3, and OPN1SW and lacked expression of common PNEC genes CALCA, GRP, and PIEZO2 (Figure 6D and E, Figure 6—figure supplement 4), we suggest that this carcinoid arose by transformation of a cell similar to PNEC #50. The gene discussed is OPN1SW; the disease is carcinoid tumor.