Fig. 6. EGFR contributes to HB-EGF-dependent eyelid closure process. (A,B) Neonatal eyelid of a wild-type (A) and a double mutant mouse carrying the HB-EGF null allele and the waved 2 EGFR allele, showing an EOB phenotype (B). (C) Penetrance of the EOB phenotype in compound mutants carrying the HB-EGF null (`d') and waved 2 (`wa2') alleles. Blue bars indicate pups with normal closed eyes; red bars indicate pups with EOB.