A mutation in c-kit expressed in ELM-I-1 cells. Nucleotide 2468 was a G both in each c-kit cDNA clone from ELM-D cells and the published wild-type c-kitsequence,37 but a C in each c-kit cDNA clone from ELM-I-1. This change results in an aspartic acid to histidine mutation at codon 814 in the predicted amino acid sequence of the mutant Kit receptor kinase domain. Direct sequencing of RT-PCR products shows that ELM-I-1 cells express both mutant and wild-type sequences.