SHH and breast cancer: In PCa, KLF4, a gene downstream of GLI1, may promote cancer progression by attenuating CD8+ T cell infiltration and suppressing CAM M2 polarization.[124] In BC, SHH is negatively correlated with carcinogenesis; basal cells expressing SHH serve as precursor lesions that develop into tumor‐initiating cells but disappear in muscle‐invasive BC.[125] However, some studies have reported that the SHH pathway promotes BC progression and chemoresistance.[126] Although its role remains debatable, the SHH pathway is essential for the development of both the bladder and prostate.