ROR2 and osteosarcoma: Although, early work showed Ror2 expression to be largely restricted to early embryogenesis with its mutation or loss resulting in various skeletal malformations in humans and mice [5], [6], [7], its expression has been reported in an increasing array of cancers including osteosarcoma, melanoma, prostate cancer, gastric cancer, gastrointestinal stromal tumor (GIST), leiomyosarcoma (LMS), colorectal cancer, squamous cell carcinoma of the head and neck and ccRCC [4], [8], [9], [10], [11], [12], [13], [14], [15], [16].