ITPR1 and breast cancer: We found that both IP3R1 and IP3R3 expression were significantly higher in BC tissue than in non-tumor tissue (IP3R1; 1.59 ± 0.04 (N = 26) vs. 1 ± 0.03 (N = 12), respectively; p = 0.02; IP3R3: 3.37 ± 0.14 (N = 29) vs. 1 ± 0.02 (N = 12), respectively; p < 0.0001) (Figure 1A).