While an important role for GM-CSF was described by Greter et al [44], and by Unkel et al using a murine model of influenza infection [35], Edelson and colleagues presented data arguing against an essential role for GM-CSF in lung αE-DC development, even though αE-DC unable to respond to GM-CSF did express reduced cell surface levels of CD103 [45]. The gene discussed is CSF2; the disease is influenza.