P4HA1 and breast cancer: Overexpression of P4HA1 has previously been seen in TNBC-BC (Xiong et al., 2018), head and neck squamous cell carcinomas (HNSCC) (Li et al., 2019), prostate (Wolf et al., 2004), melanoma (Atkinson et al., 2019), and gastric cancer (Cheng et al., 2012).