In addition, the expression level of TRPC channels may depend on the differentiation status of the cancer cells, because we found the mRNA expression of TRPC1, TRPC3, TRPC4 and TRPC6 in the low differentiation grade lung cancer was lower than that in the well differentiated cancer, which is consistent to our observation in ovarian cancer [9] and the low level expression of TRPC4 and TRPC6 in immature stem cells [38]. This evidence concerns the gene TRPC4 and ovarian cancer.