Table 2.

Additional mutations in skin metastases vs. primary breast tumors in paired cases along with data source.

References	Total Paired Cases N	Paired Cases of Skin Metastases N	Additional Molecular Alterations in Skin Metastases Not Found in Primary Breast Tumors
Schrijver et al. [57]	17	8	33 mutations (ATR, BRCA1, SMAD4, CDH1, ARID1A, ERBB2, IDH1, PIK3R1, RB1, and others)
Yates et al. [21]	Cohort 1: 7	2	4 molecular alterations (amplification of FGFR1/structural variant of TP53, indel of RB1/amplification of TERC)
	Cohort 2: 51	4	9 mutations (JAK2, NF1, TP53, AKT1, and ARID1A)
Paul et al. [58]	28	1	54 mutations (PIK3CA, TP53, and others)