PTPRD and metastatic melanoma: PTPRD homozygous or heterozygous deletion has also been reported in cutaneous squamous cell carcinoma [21,22], GBM [6,20,23,24], lung cancer [25,26], neuroblastoma [27], metastatic melanoma [28,29], squamous cell carcinoma of the vulva [30], hepatocellular carcinoma [31], and laryngeal squamous cell carcinoma [5].