ERBB3 and squamous cell carcinoma: Alternative transcripts for ERBB3 resulting in naturally occurring soluble truncated isoforms including a 1.4 kb transcript of ERBB3 in gastric cancer cell lines [64] and an additional four novel transcripts (1.6, 1.7, 2.1, and 2.3kb) from ovarian cancer cell lines [65] encouraged researchers to identify these secreted isoforms of ERBB3 in Prostate [92–95], liver [96], breast [97, 98] and squamous cell carcinoma [99].