ɹˈiːsənt stˈʌdiz hæv tʃˈælɪndʒd ðɪs mˈɑːdəl ænd ʃˈoʊd ðæt flˈoːɹ plˈeɪt dᵻɹˈaɪvdnˈɛtɹɪn wˈʌn ɪz dɪspˈɛnsəbəl fɔːɹ mˈɪdlaɪn kɹˈɔsɪŋ ænd ðæt nˈɛtɹɪn wˈʌn pɹaɪmˈɛɹᵻli dᵻɹˈaɪvz fɹʌm vɛntɹˈɪkjʊlɚ zˈoʊn pɹoʊdʒˈɛnɪɾɚz.
Recent studies have challenged this model and showed that floor plate derived-Netrin-1 is dispensable for midline crossing and that Netrin-1 primarily derives from ventricular zone progenitors.