I've heard that we can't infer heterozygosity or homozygosity for the mutations identified in MAF files, but I noticed that the MAF file's columns 11-13 may have information for inferring this info. For example
Reference_Allele Tumor_Seq_Allele1 Tumor_Seq_Allele2 G G C G G C A A C G G A C C T C C A
From a comparison of Ref and Tumor alleles, can we infer that all these mutations are heterozygous? because One tumor allele is the same as Ref allele. Is this understanding correct?