A system for generating a characterization model for a variant in a tumor sample from a subject, the system comprising: at least one processor operatively connected to a memory, the at least one processor when executing is configured to: (a) acquire a variant allele frequency input, VAFI, which comprises the allele frequency for said variant being characterized, in the tumor sample; (b) acquire values for: a genomic segment total copy number, C, for each of a plurality of genomic segments; a genomic segment minor allele copy number, M, for each of a plurality of genomic segments; and sample purity, p; (c) calculate a value for mutation type, g, which is indicative of the variant being somatic, germline, subclonal somatic, or not-distinguishable, wherein the at least one processor when executing is configured to determine g by solving for g in: VAFI = pM + g 1 − p pC + 2 1 − p; and (d) classify the type of variant based on at least one of: for a g value approximately equal to 0, classify the variant as a somatic variant; for a g value approximately equal to 1, classify the variant as a germline variant; for a g value between 0 and 1, evaluate the g value to determine that it is not a somatic classification value or a germline classification value, and classify the variant as indistinguishable; and for a g value less than 0, classify the variant as a subclonal somatic variant. (a) acquire a variant allele frequency input, VAFI, which comprises the allele frequency for said variant being characterized, in the tumor sample; (b) acquire values for: a genomic segment total copy number, C, for each of a plurality of genomic segments; a genomic segment minor allele copy number, M, for each of a plurality of genomic segments; and sample purity, p; a genomic segment total copy number, C, for each of a plurality of genomic segments; a genomic segment minor allele copy number, M, for each of a plurality of genomic segments; and sample purity, p; (c) calculate a value for mutation type, g, which is indicative of the variant being somatic, germline, subclonal somatic, or not-distinguishable, wherein the at least one processor when executing is configured to determine g by solving for g in: VAFI = pM + g 1 − p pC + 2 1 − p; and (d) classify the type of variant based on at least one of: for a g value approximately equal to 0, classify the variant as a somatic variant; for a g value approximately equal to 1, classify the variant as a germline variant; for a g value between 0 and 1, evaluate the g value to determine that it is not a somatic classification value or a germline classification value, and classify the variant as indistinguishable; and for a g value less than 0, classify the variant as a subclonal somatic variant. for a g value approximately equal to 0, classify the variant as a somatic variant; for a g value approximately equal to 1, classify the variant as a germline variant; for a g value between 0 and 1, evaluate the g value to determine that it is not a somatic classification value or a germline classification value, and classify the variant as indistinguishable; and for a g value less than 0, classify the variant as a subclonal somatic variant.