UNC5B and small cell lung carcinoma: Since netrin‐1 has been shown to promote tumor progression in various cancer indications due to its ability to block DCC and UNC5B‐induced cell death, and since our current data show that in NB and SCLC tumors, netrin‐3 is upregulated rather than netrin‐1, we first investigated whether netrin‐3 could bind to netrin‐1 receptors.