- Dalgaard T, Vitved L, Skjødt K, Thomsen B, Labouriau R, Jensen K, et al. Molecular characterization of major histocompatibility complex class I (B-F) mRNA variants from chickens differing in resistance to Marek's disease. Scand J Immunol. 2005;62:259-70 pubmed..This alternative exon 7 splice variant was also detected in other MD-susceptible haplotypes, but not in the MD-resistant B21 and B21-like haplotypes, suggesting a potential role of exon 7 in MHC-related MD resistance. ..